Ratio of Rape

i think it depends on whether it is reported or not. i know that in pakistan, most of the time rape is probably not reported due to social implications so there is no way of knowing how common it is.
moreover, i think there is no way of knowing if it happens more in open or closed societies and personally i don't think it should matter because it is wrong in any case.
having said that, I think in Pakistan and muslim countries rape may be for sexual motives since it is forbidden to practice it outside of a marriage, but also men seem to rape sisters/females to get revenge on their enemies in pakistan and similar areas like india, which is rarely the case in the west.

india is not any different from pakistan. in their society sex isn't practiced outside of marriage either.
also i think rape would be less common in the west not because people practice sex more freely, because the punishment for it is very severe compared to countries like pakistan or india.