Look at older threads on this site. The year books state how many baptisms per year. They also show how many people are missing per year. Start at looking at these threads. You’ll find the jws are greatly exaggerating their numbers.
Im willing to bet there’s less then 4 million actual baptized jws in the world and the number of ones leaving are higher then back after the 1995 change in the generation teaching, where it looks as though for a few years after they lost about 250,000 per year.