No they're not a 100% accurate. But this one is near enough.
You admit they're not 100% accurate but you assume that is close enough. Riiiiiight. All i'm saying is that there is no way to know 100%. Sure there is a low number of LGBT would would openly say they're LGBT, but the ones in closet won't say a word and there are some who weren't sure about their sexuality.
Then what do you think the percentage is 10,20,30%? Because with all due respect I would find it difficult to reconcile a species with 7 billion members in it if a high percentage of them are homosexual and therefore unlikely to have offspring of their own. Not to mention any party who actively pursued an anti gay agenda against such a large section of the electorate would be unlikely to win any elections. So why do anti gay marriage votes keep winning and the anti gay party, the GOP, keep getting such a high vote at elections?