Sexual Assault: The Numbers -- Responding to Transgender Victims of Sexual assault
According to that link, 1 in 2 transgender people experience sexual assault
in their lifetime. I bet the majority of them are the FtM. And it is quite possible that the rape happened pre-transition and was directly responsible for the gender dysphoria and desire to become a man in order to be less vulnerable. Of course, men who were raped/molested as kids may well end up with confusion about their gender.
Other cases may be where a transgender woman goes to prison. If he is housed with his sex, there is an increased likelihood of rape. Likewise, a transgender man would face risks if she was housed with the sex she identifies with.
Black Transwomen face the most risk. Mostly due to sex work and also due to homophobia in the black community.
And, let's face it, troons lie. There's a good chance that more than a few of these just did not happen.