As to “campus rape epidemic”, what is known is that women who do not attend college are if anything less safe. The logic then falls apart that women would not be attending college if the stats on college were X. They would, because no better is available anywhere else.
There’s also a degree of bait and switch here. Not all sexual assaults are rape, or even attempted rape. The wider a net is cast with the term “sexual assault”, the smaller the share of sexual assaults that fall in the very gravest category.
FBI statistics, according to an article in SLATE from 2014, have rapes (forcible or not) running at somewhat short of 30 thousand per year in the US. And on a downtrend, though a definitional change in the stats blurs that picture a bit.
There are roughly 150 million women in America, of whom maybe 8 percent are of college age, and maybe 4 are actually in college. That would be 6 million women college students. If all the rapes committed in the US were committed against these women, and not any against anyone else, that would mean that in any given year, 1/2 of 1 percent would be raped. Over their entire time in college, maybe 2 percent. But of course the reality is nothing like that. Rapists attack young women who are not college students, older women, children, men — -so the fraction of women attending college who will experience being raped while in college cannot possibly be as high as 1/2 of 1 percent. That’s a far cry from the “20 percent” figure that we are asked by implication to believe. However many the number is, it’s that many too many, and we need to work diligently to drive down the number. But the road to success begins with a clear-eyed understanding of current reality.