Mr. Justice White
delivered the opinion of the Court.
In Taylor v. Louisiana, 419 U. S. 522 (1975), this Court held that systematic exclusion of women during the jury-selection process, resulting in jury pools not “reasonably representative” of the community, denies a criminal defendant his right, under the Sixth and Fourteenth Amendments, to a petit jury selected from a fair cross section of the community. Under the system invalidated in Taylor, a woman could not serve on a jury unless she filed a written declaration of her willingness to do so. As a result, although 53% of the persons eligible for jury service were women, less than 1% of the 1,800 persons whose names were drawn from the jury wheel during the year in which appellant Taylor’s jury was chosen were female. Id., at 524.
At the time of our decision in Taylor, no other State provided that women could not serve on a jury unless they volunteered to serve. However, five States, including Missouri, provided an automatic exemption from jury service for any women requesting not to serve. Subsequent to Taylor, three of these States eliminated this exemption. Only Missouri, respondent in this case, and Tennessee continue to exempt women from jury service upon request. Today we hold that such systematic exclusion of women that results in jury venires averaging less than 15% female violates the Constitution’s fair-cross-section requirement.
I
Petitioner Duren was indicted in 1975 in the Circuit Court of Jackson County, Mo., for first-degree murder and first-degree robbery. In a pretrial motion to quash his petit jury panel, and again in a post-conviction motion for a new trial, he contended that his right to trial by a jury chosen from a fair cross section of his community was denied by provisions of Missouri law granting women who so request an automatic exemption from jury service. Both motions were denied.
At hearings on these motions, petitioner established that the jury-selection process in Jackson County begins with the annual mailing of a questionnaire to persons randomly selected from the Jackson County voter registration list. Approximately 70,000 questionnaires were mailed in 1975. The questionnaire contains a list of occupations and other categories which are the basis under Missouri law for either disqualification or exemption from jury service. Included on the questionnaire is a paragraph prominently addressed “TO WOMEN” that states in part:
“Any woman who elects not to serve will fill out this paragraph and mail this questionnaire to the jury commissioner at once.”
A similar paragraph is addressed "TO MEN OVER 65 YEARS OF AGE,” who are also statutorily exempt upon request.
The names of those sent questionnaires are placed in the master jury wheel for Jackson County, except for those returning the questionnaire who indicate disqualification or claim an applicable exemption. Summonses are mailed on a weekly basis to prospective jurors randomly drawn from the jury wheel. The summons, like the questionnaire, contains special directions to men over 65 and to women, this time advising them to return the summons by mail if they desire not to serve. The practice also is that even those women who do not return the summons are treated as having claimed exemption if they fail to appear for jury service on the appointed day. Other persons seeking to claim an exemption at this stage must make written or personal application to the court.
Petitioner established that according to the 1970 census, 54% of the adult inhabitants of Jackson County were women. He also showed that for the periods June-October 1975 and January-March 1976, 11,197 persons were summoned and that 2,992 of these, or 26.7%, were women. Of those summoned, 741 women and 4,378 men appeared for service. Thus, 14.5% (741 of 5,119) of the persons on the postsummons weekly venires during the period in which petitioner’s jury was chosen were female. In March 1976, when petitioner’s trial began, 15.5% of those on the weekly venires were women (110 of 707). Petitioner’s jury was selected from a 53-person panel on which there were 5 women; all 12 jurors chosen were men. None of the foregoing statistical evidence was disputed.
In affirming petitioner’s conviction, the Missouri Supreme Court questioned two aspects of his statistical presentation. First, it considered the census figures inadequate because they were six years old and might not precisely mirror the percentage of women registered to vote. Second, petitioner had not unequivocally demonstrated the extent to which the low percentage of women appearing for jury service was due to the automatic exemption for women, rather than to sex-neutral exemptions such as that for persons over age 65.
The court went on to hold, however, that even accepting petitioner’s statistical proof, “the number of female names in the wheel, those summoned and those appearing were well above acceptable constitutional standards.” 556 S. W. 2d 11, 15-17 (1977). We granted certiorari, 435 U. S. 1006 (1978), because of concern that the decision below is not consistent with our decision in Taylor.
II
We think that in certain crucial respects the Missouri Supreme Court misconceived the nature of the fair-cross-section inquiry set forth in Taylor. In holding that “petit juries must be drawn from a source fairly representative of the community,” 419 U. S., at 538, we explained that
“jury wheels, pools of names, panels, or venires from which juries are drawn must not systematically exclude distinctive groups in the community and thereby fail to be reasonably representative thereof.” Ibid.
In order to establish a prima facie violation of the fair-cross-section requirement, the defendant must show (1) that the group alleged to be excluded is a “distinctive” group in the community; (2) that the representation of this group in venires from which juries are selected is not fair and reasonable in relation to the number of such persons in the community; and (3) that this underrepresentation is due to systematic exclusion of the group in the jury-selection process.
A
With respect to the first part of the prima facie test, Taylor without doubt established that women “are sufficiently numerous and distinct from men” so that “if they are systematically eliminated from jury panels, the Sixth Amendment’s fair-cross-section requirement. cannot be satisfied.” Id., at 531.
B
The second prong of the prima facie case was established by petitioner’s statistical presentation. Initially, the defendant must demonstrate the percentage of the community made up of the group alleged to be underrepresented, for this is the conceptual benchmark for the Sixth Amendment fair-cross-section requirement. In Taylor, the State had stipulated that 53% of the population eligible for jury service was female, while petitioner Duren has relied upon a census measurement of the actual percentage of women in the community (54%). In the trial court, the State of Missouri never challenged these data. Although the Missouri Supreme Court speculated that changing population patterns between 1970 and 1976 and unequal voter registration by men and women rendered the census figures a questionable frame of reference, there is no evidence whatsoever in the record to suggest that the 1970 census data significantly distorted the percentage of women in Jackson County at the time of trial. Petitioner’s presentation was clearly adequate prima facie evidence of population characteristics for the purpose of making a fair-cross-section violation.
Given petitioner’s proof that in the relevant community slightly over half of the adults are women, we must disagree with the conclusion of the court below that jury venires containing approximately 15% women are “reasonably representative” of this community. If the percentage of women appearing on jury pools in Jackson County had precisely mirrored the percentage of women in the population, more than one of every two prospective jurors would have been female. In fact, less than one of every six prospective jurors was female; 85% of the average jury was male. Such a gross discrepancy between the percentage of women in jury venires and the percentage of women in the community requires the conclusion that women were not fairly represented in the source from which petit juries were drawn in Jackson County.
C
Finally, in order to establish a prima facie case, it was necessary for petitioner to show that the underrepresentation of women, generally and on his venire, was due to their systematic exclusion in the jury-selection process. Petitioner’s proof met this requirement. His undisputed demonstration that a large discrepancy occurred not just occasionally, but in every weekly venire for a period of nearly a year manifestly indicates that the cause of the underrepresentation was systematic — that is, inherent in the particular jury-selection process utilized.
Petitioner Duren’s statistics and other evidence also established when in the selection process the systematic exclusion took place. There was no indication that underrepresentation of women occurred at the first stage of the selection process— the questionnaire canvass of persons randomly selected from the relevant voter registration list. The first sign of a systematic discrepancy is at the next stage — the construction of the jury wheel from which persons are randomly summoned for service. Less than 30% of those summoned were female, demonstrating that a substantially larger number of women answering the questionnaire claimed either ineligibility or exemption from jury service. Moreover, at the summons stage women were not only given another opportunity to claim exemption, but also were presumed to have claimed exemption when they did not respond to the summons. Thus, the percentage of women at the final, venire, stage (14.5%) was much lower than the percentage of women who were summoned for service (26.7%).
The resulting disproportionate and consistent exclusion of women from the jury wheel and at the venire stage was quite obviously due to the system by which juries-were selected. Petitioner demonstrated that the underrepresentation of women in the final pool of prospective jurors was due to the operation of Missouri’s exemption criteria — whether the automatic exemption for women or other statutory exemptions — as implemented in Jackson County. Women were therefore systematically underrepresented within the meaning of Taylor.
Ill
The demonstration of a prima facie fair-cross-section violar tion by the defendant is not the end of the inquiry into whether a constitutional violation has occurred. We have explained that “States remain free to prescribe relevant qualifications for their jurors and to provide reasonable exemptions so long as it may be fairly said that the jury lists or panels are representative of the community.” Taylor, 419 U. S., at 538. However, we cautioned that “[t]he right to a proper jury cannot be overcome on merely rational grounds,” id., at 534. Rather, it requires that a significant state interest be manifestly and primarily advanced by those aspects of the jury-selection process, such as exemption criteria, that result in the disproportionate exclusion of a distinctive group.
The Supreme Court of Missouri suggested that the low-percentage of women on jury venires in Jackson County may have been due to a greater number of women than of men qualifying for or ‘claiming permissible exemptions, such as those for persons over 65, teachers, and government workers. 556 S. W. 2d, at 16. Respondent further argues that petitioner has not proved that the exemption for women had “any effect” on or was responsible for the underrepresentation of women on venires. Brief for Respondent 15.
However, once the defendant has made a prima facie showing of an infringement of his constitutional right to a jury drawn from a fair cross section of the community, it is the State that bears the burden of justifying this infringement by showing attainment of a fair cross section to be incompatible with a significant state interest. See Taylor, 419 U. S., at 533-535. Assuming, arguendo, that the exemptions mentioned by the court below would justify failure to achieve a fair community cross section on jury venires, the State must demonstrate that these exemptions caused the underrepresentation complained of. The record contains no such proof, and mere suggestions or assertions to that effect are insufficient.
The other possible cause of the disproportionate exclusion of women on Jackson County jury venires is, of course, the automatic exemption for women. Neither the Missouri Supreme Court nor respondent in its brief has offered any substantial justification for this exemption. In response to questioning at oral argument, counsel for respondent ventured that the only state interest advanced by the exemption is safeguarding the important role played by women in home and family fife. But exempting all women because of the preclusive domestic responsibilities of some women is insufficient justification for their disproportionate exclusion on jury venires. What we stated in Taylor with respect to the system there challenged under which women could “opt in” for jury service is equally applicable to Missouri’s “opt out” exemption:
“It is untenable to suggest these days that it would be a special hardship for each and every woman to perform jury service or that society cannot spare any women from their present duties. This may be the case with many, and it may be burdensome to sort out those who should be exempted from those who should serve. But that task is performed in the case of men, and the administrative convenience in dealing with women as a class is insufficient justification for diluting the quality of community judgment represented by the jury in criminal trials.
“If it was ever the case that women were unqualified to sit on juries or were so situated that none of them should be required to perform jury service, that time has long since passed.” 419 U. S., at 534-535, 537 (footnote omitted).
We recognize that a State may have an important interest in assuring that those members of the family responsible for the care of children are available to do so. An exemption appropriately tailored to this interest would, we think, survive a fair-cross-section challenge. We stress, however, that the constitutional guarantee to a jury drawn from a fair cross section of the community requires that States exercise proper caution in exempting broad categories of persons from jury service. Although most occupational and other reasonable exemptions may inevitably involve some degree of overinclu-siveness or underinclusiveness, any category expressly limited to a group in the community of sufficient magnitude and distinctiveness so as to be within the fair-cross-section requirement — such as women — runs the danger of resulting in under-representation sufficient to constitute a prima facie violation of that constitutional requirement. We also repeat the observation made in Taylor that it is unlikely that reasonable exemptions, such as those based on special hardship, incapacity, or community needs, “would pose substantial threats that the remaining pool of jurors would not be representative of the community.” Id., at 534.
The judgment of the Missouri Supreme Court is reversed, and the case is remanded for further proceedings not inconsistent with this opinion.
So ordered.
See Taylor v. Louisiana, 419 U. S., at 526-531, 538; Duncan v. Louisiana, 391 U. S. 145 (1968). A criminal defendant has standing to challenge exclusion resulting in a violation of the fair-cross-section requirement, whether or not he is a member of the excluded class. See Taylor, supra, at 526.
See La. Const., Art. VII, §41 (1921), and La. Code Crim. Proc., Art 402 (West 1967), reproduced in 419 U. S., at 523 nn. 1 and 2.
Two other States, New Hampshire and Florida, had recently abolished similar provisions requiring otherwise qualified women to volunteer for jury service. See N. H. Rev. Stat. Ann. § 500:1 (1955), repealed by 1967 N. H. Laws. ch. 100, § 1; Fla. Stat. §40.01 (1) (1961), repealed by 1967 Fla. Laws, ch. 67-154, § 1. The current provisions are at N. H. Rev. Stat. Ann. § 500-A:2 (Supp. 1977) (providing exemption for women caring for children under age 12); Fla. Stat. § 40.01 (1) (1977) (providing exemption for pregnant women and women with children under age 15).
Ga. Code § 59-124 (1965); Mo. Const., Art. 1, § 22 (b), Mo. Rev. Stat. §494.031 (2) (Supp. 1978); N. Y. Jud. Law §§ 507 (7), 599 (7), 665 (7) (McKinney 1964); R. I. Gen. Laws §9-9-11 (1969); Tenn. Code Ann. §22-101 (Supp. 1978), §22-108 (1955). In addition, Alabama did not allow women to serve on juries until 1966, see Ala. Code, Tit. 30, § 21 (1958), in which year they were provided an exemption “for good cause shown.” 1966 Ala. Acts, p. 429, §4; Ala. Code, Tit. 30, §21 (Supp. 1973).
1975 Ga. Laws, pp. 779-780; 1975 N. Y. Laws, chs. 4, 21; 1975 R. I. Pub. Laws, ch. 233, § 1. The current previsions relating to qualification for jury service are at Ga. Code Ann. § 59-112 (Supp. 1978); N. Y. Jud. Law § 512 (McKinney Supp. 1978); R. I, Gen. Laws §§ 9-9-1, 9-9-11 (Supp. 1977). Alabama has replaced its exemption of women for cause, see n. 4, supra, with a general provision setting out qualifications for jury service. Ala. Code § 12-16-43 (1975).
The Tennessee Supreme Court has stated that the constitutionality of the exemption for women is “highly suspect” but has declined to test the exemption “pursuant to the principles announced in Taylor until a record is presented that reflects the consequences of [its] operation,” Scharff v. State, 551 S. W. 2d 671, 676 (1977). On at least one occasion, the Tennessee House of Representatives has passed a bill that would repeal that State’s exemption for women, see H. R. 105, 89th Assembly, 1st Sess. (1975). See generally Daughtrey, Cross Sectionalism in Jury-Selection Procedures After Taylor v. Louisiana, 43 Tenn. L. Rev. 1, 49-50 (1975).
In Massachusetts, the court may excuse any woman requesting not to serve in a case involving sex crimes. Mass. Gen. Laws Ann., ch. 234, § 1A (West 1959).
Missouri Const., Art. 1, §22 (b), provides:
“No citizen shall be disqualified from jury service because of sex, but the court shall excuse any woman who requests exemption therefrom before being sworn as a juror.”
This constitutional mandate is implemented by Mo. Rev. Stat. § 494.031 (2) (Supp. 1978), providing:
“The following persons, shall, upon their timely application to the court, be excused from service as a juror, either grand or petit:
“(2) Any woman who requests exemption before being sworn as a juror.”
See also § 497.030 (Supp. 1978) and n. 11, infra.
Felons, illiterates, attorneys, judges, members of the Armed Forces, and certain others are ineligible for jury service. Mo. Rev. Stat. § 494.020 (Supp. 1978).
In addition to women, the following are exempted from jury service upon request: persons over age 65, medical doctors, clergy, teachers, persons who performed jury service within the preceding year, “any person whose absence from his regular place of employment would, in the judgment of the court, tend materially and adversely to affect the public safety, health, welfare or interest,” and “[a]ny person upon whom service as a juror would in the judgment of the court impose an undue hardship.” §494.031 (Supp. 1978).
The use and form of this questionnaire are prescribed by a state statute applicable only to Jackson County. §497.130 (Supp. 1978).
Ibid.; App. 43»
See n. 10, supra.
This practice in Jackson County with respect to women not appearing for service is not authorized by statute, and persons failing to report for jury service are subject to contempt of court, Mo. Rev. Stat. §494.080 (1952). However, Mo. Const., Art. 1, §22 (b), allows a woman to claim exemption at any time “before being sworn as a juror,” n. 8, supra.
The record does not reveal whether any summonses were mailed in November or December 1975.
The smallest percentage of women appearing on a jury venire, 7.3%, occurred the first week in January 1976 (12 women of 164 appearing), and the largest percentage of women appearing, 21.8%, occurred in March 1976 (32 women of 147 appearing). App. 8, 45.
556 S. W. 2d 11, 16 (Mo. 1977).
Brief for Respondent 5.
The decision below also rejected petitioner’s challenge under the Equal Protection Clause of the Fourteenth Amendment. This challenge has not been renewed before this Court.
We further explained that this requirement does not mean “that petit juries actually chosen must mirror the community,” 419 U. S., at 538.
Under Louisiana law at the time of appellant Taylor’s trial, all persons not indicted for or convicted of a felony, who were 21 years of age or older, and who were literate in English and physically and mentally capable were eligible for jury duty. La. Code Crim. Proc., Art. 401 (West 1967).
This speculation is belied by the U. S. Dept, of Commerce, Bureau of the Census, Current Population Reports: Voting and Registration in the Election of November 1976, Table 5 (1978), showing that 69.9% of the women and 71.1% of the men in Missouri are registered to vote.
The opinion below found additional fault with the census data in that voter registration lists include persons aged 18 to 21, while the census data included only persons 21 years of age and older. See 556 S. W. 2d, at 16. However, the 1970 census data not only included a summary row showing that 54% of persons 21 years of age and older were women, but also included data showing that an even greater percentage of persons between the ages of 18 and 21 were women. App. 39. In any event, the fair-cross-section requirement involves a comparison of the makeup of jury venires or other sources from which jurors are drawn with the makeup of the community, not of voter registration lists.
We have previously accepted 6-year-old census data as adequate proof of the percentage of eligible jurors who are black. Alexander v. Louisiana, 405 U. S. 625, 627 (1972). That case involved an equal protection challenge to a jury-selection process. Although proof of such a claim is in certain respects not analogous to proof of a cross-section violation, see n. 26, infra, Alexander, like the case at hand, involved establishing as a benchmark the percentage of the excluded group in the relevant population.
The Federal District Court encompassing Jackson County does not have an automatic exemption for women, but does provide occupational exemptions similar to those provided by the State of Missouri, and also has a child-care exemption — albeit, one limited to women. See Amended Plans of the United States District Court for the Western District of Missouri for Random Selection and Service of Grand and Petit Jurors § 14 (1972). Fifty-three percent of the persons on the master jury wheel and 39.8% of actual jurors are women. See 556 S. W. 2d, at 24, and nn. 3, 4 (Seiler, J., dissenting).
In arguing that the reduction in the number of women available as jurors from approximately 54% of the community to 14.5% of jury venires is prima facie proof of “unconstitutional underrepresentation,” petitioner and the United States, as amicus curiae, cite Castaneda v. Partida, 430 U. S. 482, 496 (1977); Alexander v. Louisiana, supra, at 629; Turner v. Fouche, 396 U. S. 346, 359 (1970); and Whitus v. Georgia, 385 U. S. 545, 552 (1967). Those equal protection challenges to jury selection and composition are not entirely analogous to the case at hand. In the cited cases, the significant discrepancy shown by the statistics not only indicated discriminatory effect but also was one form of evidence of another essential element of the constitutional violation — discriminatory purpose. Such evidence is subject to rebuttal evidence either that discriminatory purpose was not involved or that such purpose did not have a determinative effect. See Castaneda, supra, at 493-495; Mt. Healthy City Bd. of Ed. v. Doyle, 429 U. S. 274, 287 (1977). In contrast, in Sixth Amendment fair-cross-section cases, systematic disproportion itself demonstrates an infringement of the defendant’s interest in a jury chosen from a fair community cross section. The only remaining question is whether there is adequate justification for this infringement.
Tr. of Oral Arg. 28.