In the numbers we are seeing now? Bear in mind that the largest cohort referred to UK gender clinics is adolescent girls.
If you're talking about males playing female roles on the Elizabethan stage, surely that's because women weren't allowed to act. And they didn't seem to need genital inspections to know who was banned from the stage and who wasn't. Shakespeare writing As You Like It, where characters pretend to be the opposite sex for comic effect, isn't exactly evidence of the existence of a trans community either. The jokes rely on the audience knowing the characters aren't the sex they pretend to be, just like in Some Like It Hot. Otherwise it wouldn't be funny.
I don't doubt that there have people throughout history who have 'lived' as the opposite sex. When it's been women though it's questionable as to whether that indicates gender dysphoria as we term it today or simply adopting a male persona in order to do stuff that you couldn't do as a woman, like have certain careers, or live in a relationship with another woman. Without an individual's own words to confirm it, I think it's erasing women's achievements to retrospectively call them transgender simply because they were gender non conforming or displayed 'masculine' qualities like bravery and leadership, eg Joan of Arc.
Two interesting historical figures in this respect that have been debated about:
https://blog.epicchq.com/herstory-irelands-epic-women-dr-james-barry
https://en.m.wikipedia.org/wiki/Billy_Tipton
(There's a much better account of Billy Tipton's life than the Wiki page but I can't find it at the moment).
Historically, they didn't need to look under bathroom doors to decide who couldn't vote. Or who was to be subjected to female genital mutilation, or thrown on a funeral pyre, or forced into child marriage. This idea that all of a sudden none of us know what sex is really is a bit odd.