Google has now opened its Google Books database for researchers. Using books as a proxy for public interest is also problematic, but these data do at least give you an impression of what scientists, scholars and fiction authors think about their usefulness.
"Since 2004, Google has digitized more than 15 million books worldwide. The datasets we’re making available today to further humanities research are based on a subset of that corpus, weighing in at 500 billion words from 5.2 million books in Chinese, English, French, German, Russian, and Spanish. The datasets contain phrases of up to five words with counts of how often they occurred in each year."
I have done a search comparing the use of some important transgender terms, namely: "transvestite", "crossdresser", "transsexual" and "transgender".
Later on, I will see if I can find the time to look at variants of the various words.
Click on image to enlarge, or go to Google Ngram to study it.
As far as I can see, there are no surprises here.
The first term for any transgender condition was "transvestite" (although the meaning was soon narrowed down to "crossdresser".) It was born in the early 19th century.
"Transsexual" became popular in the early 1960s, while "transgender" used as an umbrella term, appeared in the 1990s. Both are still climbing, which may indicate an increasing interest in the topics.
The use of word "crossdresser", as a replacement for "transvestite", has not taken off yet.
As for the terms "autogynephilia" and "autoandrophilia", the interest in "autogynephilia" among scholars and authors is increasing. The word" autoandrophilia" is not found at all.