From Una’s post in the other thread in IMHO:
I’m not sure of the exact breakdown of homo- vs bi-, if such a statistic exists, but it appears that a large number of MTF are attracted to women and a significant-but-not-majority number of FTM are attracted to men. I’m fairly sure that in both cases the number is not even close to the proportion of homo/bisexual:straight for cis individuals. (I’m not sure of the exact number, or if my statistic is accurate, but I’ve heard figures around 10% for rates of cis homo/bisexuality).