my last comment for today
It seems that you're saying that JW growth rate (baptisms) is greater than JW birth rate, and that therefore, there must be JW recruits from outside JWdom. In other words, it seems that you're saying that if, for example, JW growth (baptisms) is 1.5%, and birth rate among JWs is only 1%, that some of those baptized must be coming from the outside due to the preaching work. If that's what you're saying, then your argument is flawed for several reasons.
birthrate about 1.5% death rate 0.8% df'd/da'd/inactive about 0.4%
so if you look only at the birth rate and death/df'd rate you will see that there will be (from births) a net annual growth of 0.3% left
but instead of that the actual annual growth is between 2 and 2.5%
So the question is who are those people that represent between 1.7% and 2.2% ? I agree that a part of them can be other kind of family members (which in my opinion still fall under the witnessing/preaching work) but still a large part of the growth must come from outsiders.