Different surveys put the numbers at different rates. But Male to Female Transgender only mess with surgery below the belt in about 20% of cases. 4 in 5 do not.

Now other forms of surgery are higher and more common for example they may have surgery of the breasts in a female to male, or have the adam's apple removed in a male to female, and so on...aka surgeries of other forms occur in much higher amounts.

Hormones may occur in much higher amounts

But surgery involving the sexual gonads are only about 1 in 5 transgender people. But different studies say different numbers.