My guess is that there still is a "rebound" and a decline going on at the same time. The rebound is inactive or partially active JWs becoming (more) regularly active (fear due to ISIS, the Syria war, the big stream of refugees etc.). This rebound has been going on for a couple of years now since the economic depression (taken from jwfacts.com statistics page). This is why the average publishers is going up.
At the same time many JWs are fading/leaving, and there are so many that even though new people are coming in, just as many are exiting at the moment. This is why the peak is only such a little bit higher.
If this is true, then next year I expect also a standstill in average publishers growth, and after this a decline setting in. I hope things will settle a bit in the Middle East, and the economy will continue to pick up. So far not really convincing, people in general are still a negative about the future and therefore not spending much; delaying an economic boost.
I also noticed this year there still has been in increase in both spending and Bethelites. Spending increased about 5% ($224M to $236M). Evidently (pun intended!) the GB was still quite hopeful in their May broadcast, or they can't change direction as fast as they like. In that case this end year's news about the cuts should show next year. 2016 is going to be interesting year!