Hi Alex,
It seems to me getting any sort of reasonably accurate statistics on a topic people lie about so much isn't likely is it.  and anyway, 35% of men?  aren't they all likely to be gay?
My personal opinion, my feel of it is that we have reached a tipping point and straight is on the decline.  But it's a real thing.  emotionally not set up to handle being cuckolded or dominated by wife even though that happens a lot one way or another with straight husbands / gay wives.