A new report from the U.S. Justice Department finds that only 20 percent of female college students who are victims of rape or sexual assault report the incident to police.

The report was compiled by the department's Bureau of Justice Statistics' National Crime Victimization Survey. The Justice Department says the NCVS uses in-person and telephone interviews to collect data with a nationally representative sample of households.

The Justice Department report finds that a smaller percentage of women in college report rape or sexual assault to police than do women of the same age who are not in college. Thirty-two percent of women 18-24 not in college who are victims of a rape or sexual assault report it to police.

Among women in college, 26 percent of victims of rape or sexual assault said they did not report the crime to police because it was a personal matter. Twenty percent of student victims who did not report to police said they were afraid of reprisal. Nineteen percent said they did not report it because the police would not or could not do anything to help. And 12 percent of the student victims said the assault was not important enough to report.

The survey found that in 2013, women 18-24 were equally likely to be the victims of sexual assault or rape whether they were in college or not. In 2013, up to .043 percent of women told surveyors they were the victim a rape or sexual assault in the last six months.

But looking at numbers over a longer period, which the researchers say are more reliable, women 18-24 who are not in college are 1.2 times more likely to be the victims of rape or sexual assault than women of the same age in college. Those numbers were from 1995 to 2013.

The report finds that men make up a larger proportion of victims of rape or sexual assault if they are in college than not. From 1995 to 2013, 17 percent of rape and sexual assault victims on colleges campuses were men, according to the report. Men only accounted for 4 percent of victims among non-students.

Eight Massachusetts colleges and universities currently are being investigated by the U.S. Department of Education Office for Civil Rights for sexual violence, including two campuses of the University of Massachusetts — Amherst and Dartmouth. Harvard University's undergraduate college and its law school are both under investigation.