Seems there was some problems with the way they were derived.
Like, a woman who says she wasn't a victim of rape, still might be considered by the survey as a victim of rape.
All in here: US Dep of Justice
The actual figure (rape and sexual assault) is about 0.6% of college students, and slightly higher for women in 18-24 that are non college students. Cases of sexual assault have been on the decline for decades as well.
More information on how some of the other statistics were derived: Bad stats
According to that system of grading, I'm a serial rapist because I've had sex with my wife after she had been drinking...mind you, that also means I was raped by her at the time too, but, male figures were excluded. I feel so violated now.