Having over 50 years in the religion, I look back and have to agree with previous posters that I know more who have left the religion than those who have stayed in the religion. And of course, of those who "stayed in", there are many like me, that are "in under false pretense". We are "in" because there is an "inactive" Publsiher Card in a box in a Congregation nearby and because we make the occasional meeting for the sake of family and because we still "talk the talk" when we are in a JW social group.
IMO there are many more Former-JWs than there are current JWs. That's clearly true in the "western world" where the internet thrives.
Most former JWs are just not very vocal about it, because they don't want the repercutions that would result or because they've moved on with their lives and don't give a rattsazz about it.
Doc