I would guess it is a smaller percentage than our media would lead us to believe. Most gay men portrayed in movies/TV shows are silk scarf wearing, limp-wristed, drama queens like in the movie "The Birdcage." When I lived in San Francisco, this type of gay guy was here and there but the majority were regular men with regular jobs and no silk scarves. More in touch with their feminine side, to be sure, but not exactly feminine. Couldn't give you a number, but definitely less than 20%; however, that has only been my observation.
Interestingly enough, I was watching the movie "The Rock" the other day..a balls-to-the-wall thriller with Nick Cage and Sean Connery. Very masculine movie. The one gay guy was a femmy hairdresser. Go figure!