The fact...is that in any sufficiently large gathering of people, somewhere around ten percent (give or take a percentage point) will be homosexual.

I don't think the research has been done widely enough that justifies the term "fact". Maybe the figure is lower, maybe it is higher. Extrapolating from the limited local research that has been done is really a matter of speculation.

In any case talk about percentages is surely pretty irrelevant, either way. If the actual figure was one per cent or twenty per cent, what difference would that make to the rights or wrongs of it all?