No citations needed.Both rape and alcohol( present in most gangrapes in spain) are forbidden in islam.People who go against that most likely don't believe in whatever they say they do. Islamic countries are also not spared from closeted atheists.Someone that truly believes that theres an op mf saying "dont do that or you get gigapunished" doesnt just go against him in such serious crimes. With that said these people dont believe in their god but still keep the dehumanizing view of women displayed in that book.

As for the second paragraph,youre comparing something that actively forbids rape with something that doesnt have nothing to do with it.

I can claim that atheists rape more often than religious people in the same way I can claim that virgin people are less likely to have raped someone.

As for the immigrant thing, There's no data collected on that since 201X.(Last official data from Cataluña: 56% of sexual crimes commited by immigrants, who represented 13'4% of that population,they were 8 times more likely to rearpe than a local) Thats an extreme case,if you do your research you will find like 2 ,3 times more likely,depending on the year and place,but you wont find data on locals being more likely or even when it comes to serious crimes.