Hello hijosdelawatch and welcome to the forum! I think there are many people hiding within the walls of the Kingdomhalls, but getting a count is impossible at the moment.
4 out of 9 of the friends I have since I was a child left the "truth" in the past, 3 of them faded. I also know some friends from other congregations with doubts.
I was a very convinced JW before and even aux pioneered the months I could. I think the brothers can't imagine how I think now.