I was wondering if there was perhaps a correlation between the figures and how they were handling matters. Seems you may be on to something!
We cannot always know why a sample will be populated as we find it, but in cases where we can't be sure sometimes we can make good guesses based on available evidence.
Regardless, a population value we find against a given sample size will be whatever it is. In terms of extrapolation our duty is to do it responsibly and not to a given result. In this case, beginning about 25 years ago Watchtower gave steam to an effort to have local elders give special treatment to reports of sexual child abuse. Taking a look at the overall annual levels of reported cases of perpetrators, and specifically to cases involving JWs or anyone with standing in a congregation, will provide a good glimpse into whatever consequences resulted from this policy shift. As I have time to work on this I'll share it. It's not rocket science. It just takes time.