Maybe the answer is communism (trigger warning for the snowflakes). With a more equal distribution of wealth, there wouldn't be the rich and resourceful being able to build a fortress (with bought politicians, bought police, expensive lawyers) that would allow abuse against the less resourceful...
It may be difficult to find a decent historical accounting, but I can't think of any worse environment than the unaccountable all-male single-Party hierarchy of the Communist states for generating sexual assault on a massive scale.