>I am not saying that joking about rape is okay if "only" 1 in 40 women in the audience has been raped. Just that the figures are questionable.

They certainly are. FBI labs, who had every incentive to find otherwise, has discovered that, of every 100 sex crime reports filed by women, between 20 and 40 of them are false:

"False Rape Accusations May Be More Common Than Thought":

http://www.foxnews.com/story/0,2933,194032,00.html

Researched by Wendy McElroy, editor of ifeminists.com (who also had every incentive to find otherwise, and who expected to).

Along those lines:

This study by forensic science researcher, Birgitte Schmidt Astrup, found that consensual sexual intercourse often produces genital lesions:

http://www.fsijournal.org/article/S0379-0738(11)00563-9/abst...

It's interesting, because the finding of genital lesions sometimes decide the outcome of rape cases.