Interesting. If the numbers are real, they're still outpacing the global population increase rate.
Again, assuming the numbers are legit (by that I mean they weren't fudged by the Society), the growth has to be coming from the third world.
All evidence seems to suggest that in the developed world the "growth" is coming from within, children born in the religion. But you would think this wouldn't be enough to keep pace with those publishers who die every year and those who are DF'd or simply fall away.