A much more likely explanation: professionals and graduates are simply exposed to less risk (e.g. they spend more time studying, away from parties and bars).
That was my first thought too, and I agree with the point you're making. However, if the question being asked is "have you ever in your life..." then we're also asking about those people's undergraduate experiences. I'm not sure that you could successfully argue that the vast majority of sorority/fraternity crowd doesn't go on to graduate.
Oddly enough, graduates and professionals report WAY lower rates. So, that means the increase in rape/non-consentual penetration/sexual touching by force is a recent event.
Or else there is a lot of wrong self reporting in these studies. It could be that students of previous years took responsibility for their own boozing and sleeping around without hyperanalyzing and reevaluating it later in light of 2015 feminist attitudes. Not to say that date rape isn't real, just that drunken sleeping around is sometimes something that both people walk into intentionally, and there is a lot of immaturity and unwillingness to take responsibility for one's own behavior out there, particularly when "blame the male" is a convenient cop out.
OK, I'm done ranting now. Disclosure: I didn't drink in college, and I hope my own kids stay far from that whole crowd.
So here's a different viewpoint. Speaking as an atheist, I am so far removed from all the religious groups that they are indistinguishably worshiping the same absurd stone-age fantasy.
I hate to interrupt your enjoyable session of patting yourself on the back, but have to point out that your attitude is not scientific. If you take a measurement and round it unnecessarily, you are throwing away part of your data. Just enjoying the look of the nice round numbers may be good for your personal psychological well being, I suppose.
So the real question is, who are these people making decisions, and why did they make those decisions? It's odd that you don't seem to recognize that.
"There is no god." "Mohammed was a false prophet." Either of those statements is sufficient for militant Islam to want to chop off my head, as I said either sooner or later as they see their way clear. It is the job of civilized governments to constrain and box in militant Islam so it can't expand and chop off heads and blow people up in any wider of a sphere than necessary. It is distinctly NOT the job of civilized governments to censor our lovable albeit loud mouthed atheists to make the Muslims happy.
Consequently, the question of why a particular militant Islamic group goes murder-crazy at a particular moment may in some cases be purely academic and moot for policy purposes.
Except, of course that there has been surveys done of French Moslems (by the Pew Research Institute if memory serves well), that tend to prove they are the least radicalized and best integrated of all European Moslem communities. You really have no idea what you are talking about, so please just STFU.
After rampant reports of burned cars and attacks on Jews in Paris, I'd really hate to see what poorly integrated Muslim populations looked like.
Or is it the money and your pension fund you're thinking of protecting?
Seriously, what do you mean by that, my dear AC? If there's money in here for me, I would love to know about it.
Now you have families where both parents work two or three jobs and still can't improve their economic outlook.
I'll grant that there are some families like that. Most in that situation shoot themselves in the foot by spending beyond their means.
"Help Mr. Wizard!" -- Tennessee Tuxedo