It highly depends on your definition of trans. Some estimates place the rate of trans people at ~1.2%. If 1 in 10 trans people are athletes, then that'd be about 6x more common than intersex.

https://usafacts.org/articles/what-percentage-of-the-us-popu...

If my mother had two wheels she'd be a bicycle. Whenever these issues come up the number of trans athletes is always... one. Sometimes two.