Interestingly, that correlation does exist but people like to get the causal relationship exactly backward. The way people like to construe it is like this:
First, someone is sexually abused. Then, they become trans as a result.
This causal relationship is backwards. It’s actually:
First, someone comes out as trans. Then, they are sexually abused.
Since trans people are still the victim of hate crimes, if they come out they put themselves in these kinds of risks.