Eh i dont know about that. I think it would be WAY more common than the muggle world, if only because of the death eaters.

Cannon includes many ways in which a rape can happen and never be discovered, especially if that rape is of a muggle by a wizard. Even ignoring some of the more obvious aspects like so called "love potions", the wizarding world memory charms muggles at an alarming rate (this IS implied in canon).

So even ignoring rape within the wizarding world, the rate or rape would likely be way higher due to how many viewed muggles.

Now moving towards the wizarding world, its also possible it's a bit more likely than the muggle world if you account for population differences. This is likely solely because of traditions and the fracturing of wizarding society based upon the recent conflicts and the ripple effects they would have within the less visible parts of wizarding society.