These stats that are usually used include "sexual assault plus rape" to get their count (typically, the US Transgender Survey, 2015).
These are numbers from the United States.
When you go to the source material for this claim (USTS'15), you'll discover that among the trans-identified, females (whatever they identify as) are more at risk than males. The two generalized sources for this, USTS, above, and HRC put TW at 47-50% likely to experience sexual assault and/or rape.
But if you go to the National Sexual Violence Resource Center, you'll find that the combined rates are higher for all women as well as for bi- men than trans folks.
All trans- people, M and F: 47% USTS, 50% HRC
transmen: 51%
all "nonbinary females": 58%
lesbians: 57%
bisexual women: 80%
heterosexual women: 55%
transwomen: 37%
all "nonbinary males": 41%
gay men: 41%
bisexual men: 48%
heterosexual men: 22%
"crossdressers": 19%
Note, that the NSVRC used "1 in 5" for its rough estimate of women who are raped; some sources say "1 in 3", so the above numbers are a low estimate.
If I did it properly, here is a chart from the 2015 USTS (p.205) going into this topic.