In 2014 they had a special month (April or May, I forget) which allowed only 30 hours to aux pioneer. It was a new initiative, and in our congregation loads of people did it, something like 70 out of 120 publishers. The repeat of the same thing in 2015 had much less response. I think this would explain a lot of the drop off in aux pioneers in 2015.
Of course lowering the bar increases the statistics, but eventually they will run out of options.