I looked at all the pictures I took at the museum of Fine Arts of Angers (France), since I still have all of them on my hard drive while the ones I took at Rennes are both on my hard drive and on Commons servers. I actually realized, at least concerning Angers, that they were an almost equal displaying of male and female tits (my mesure of "partial nudity"), at least for adults. One painting even shows a "fully" clothed woman with three almost nude men. (the meta data / description part is crappy, I'll fixed it "tomorrow", meaning in eight hours).

Thank you Wikimedia movement, I was not creepy enougth with always thinking "Category:women facing right in red dresses" while visiting a museum, now I will count male vs female tits :D