The numbers probably changed rather dramatically after the gay rights movement. When I was young, the idea of a "gold star" especially for a lesbian was rare, because it had been rare to have the opportunity to come out until later in life, and people had been expected by peers to be dating in high school. Plenty of people "lost their virginity" or had standard hetero relationships during their adolescence/ college years, before figuring out or making public what they really wanted.

Now it's so well established that gay is a normal possibility that kids come out even before their first kiss and don't worry as much about hiding it from the world - maybe they won't share it with certain individuals, but most aren't in the closet to the degree that they have full relationships to try to fit in while they figure out who they are. Except of course, that things are changing again as a new generation is introduced to the idea that it's bigoted to have a "genital preference"...