The problem is that you focusing on assaults as the key issue, and advancing the argument that as there is little or no evidence, everything is fine.The claim put forth is that it does happen, and is self evidently inevitable. I don't find any higher burden on myself to provide negative evidence, other than to point out that if it was happening, it should be observable.
You have not been listening to the female posters who have been pointing out that the issue is far wider, especially the impact of the male gaze on privacy and dignity, and the impact via self-exclusion of females, which IS documented, especially in schools which have introduced gender neutral toilets.
