I haven't met anyone that has said that they consider themselves "non-binary", "transsexual", "transgender", or any of the other subtly different labels that they could use, but part of the current zeitgeist, especially within socially liberal-leaning circles, is to spread awareness of how diverse human sexuality is.
I don't think that there are really solid numbers for how different people identify themselves. The information would have to be self-reported, and since there would still be some social stigma attached in many places, I doubt that a survey would end up being very accurate.