> Compared to 20 years ago, being openly transgender was far more taboo, so it follows that people were less willing to identify as transgender for these kinds of surveys.
Maybe we'll know 20 years from now, because it is commonly accepted.
If the rate stays mostly flat, when it is acceptable, then we probably had no increase in the previous 20 years (from now).
If the rate of the next 20 years is trending up, then it is likely that it was trending up before it became acceptable.
Do you think being transgender is truly accepted now and there is no barrier to coming out as trans? The 20 years thing only makes sense if we are at "peak acceptance" - and it's easy to see that we are extraordinarily far from anything like that. Even for homosexuality, which has become much more accepted in the USA and many European countries in the last few years, there is still significant stigma associated with coming out in a large number of families and social groups - a minority, hopefully, but a very large one. Trans identities are nowhere near as acceptable as being gay, so any comparison will be heavily skewed by people's willingness to share, or even to accept this for themselves.
Maybe we'll know 20 years from now, because it is commonly accepted.
If the rate stays mostly flat, when it is acceptable, then we probably had no increase in the previous 20 years (from now).
If the rate of the next 20 years is trending up, then it is likely that it was trending up before it became acceptable.