text: the proportion who had used effective methods, by age group Age groupsProportion who had used birth control methodsProportion who had used effective birth control methods 15-19 0.07 0.03 20-24 0.36 0.24 25-29 0.59 0.40 30-34 0.63 0.46 35-39 0.61 0.41 40-44 0.43 0.29 45-49 0.27 0.14 Total 0.39 0.26 (a) Women who stated that they or their husband had been sterilized or that they were using contraceptive pills, injections, condoms or intrauterine devices. E/1986/3/Add.l3 page 17 Proportion of users of effective contraceptive methods among the total of married or cohabiting women, by level of schooling Proportion Did not go to school 0 0.22 Incomplete primary 1-5 0.38 Complete primary 6 0.45 Secondary 7-9 0.47 Technical education 10-12 0.56 Baccalaureate or higher education 12 or more 0.53 Total 0.40 Proportion of users of effective contraceptive methods amonq the total number of married or cohabitinq women. by size of locality Size of locality of residence Proportion Fewer than 20,000 inhabitants 0.32 More than 20,000 inhabitants 0.48 Metropolitan areas of Mexico City, Guadalajara and Monterrey 0.52 Total 0.40 Proportion of users of effective contraceptive methods amonq the total number of married or cohabiting women, by number of live births Number of live birthsProportion of users of effective contraceptive methods None 0.06 One and two 0.41 Three 0.48 Four and five 0.53 Six or more 0.36 Total 0.40 69. Mexico's population policy forms part of the country's overall development policy and is based on a himnanist concept that respects the liberty of the individual and the decisions of the family. The Government of Mexico is aware that demographic policy is in line with social needs and that its aim is to help the overall welfare of families and the communities. 70. The results of the National Demographic Survey illustrate the trends 
analysis: The text appears to be related to the demographic and reproductive health of women in Mexico, discussing the use of birth control methods and their effectiveness. It also mentions the country's population policy and its aim to promote the overall welfare of families and communities. This suggests that the text is related to the field of health, specifically reproductive health.