Rape prevalence among women in the U.S. (the percentage of women who experienced rape at least once in their lifetime so far) is in the range of 15–20%, with different studies disagreeing with each other. An early 1987 study found that one in four American women will be the victim of a rape or attempted rape in her lifetime, and 84% of those will know their attacker. However, only 27% of American women whose sexual assault met the legal definition of rape think of themselves as rape victims, and only about 5% report their rape. One study of rape on American college campuses found that 13% of acquaintance rapes, and 35% of attempted acquaintance rapes, took place during a date, and another found that 22% of female rape victims had been raped by a current or former date, boyfriend or girlfriend, and another 20% by a spouse or former spouse. A 2007 American study found black non-Hispanic students were likeliest to be victims of dating violence, followed by Hispanic students and then white non-Hispanic students.