I dunno slimboy,
The memorial attendance has hovered around 20 mil for the past 5 years. I really believe 2015/16 (if figures aren't massaged) will show peak publishers give or take 1% for the next few years. I would be surprised if the peak goes beyond 8.5 million unless they go mainstream - as in stopping the shunning.
Their baptisms are down on the peaks of 300K a year they reached at one point.
If it wasn't for western medicine and the drop in smoking worldwide they would have lost a lot more old ones by now, but they can't live forever! (Pun intended)