Another interesting statistic is the number of congregations. It is also steadily declining in growth.
2011-2012, an additional 2316
2012-2013, an additional 2104
2013-2014, an additional 1593
I'm curious about what warrants these additional congregations in the first place. With 275,581 baptized, this amounts to an average of 2.38 additional publishers per congregation (using the 2014 number of congregations, or 2.42 using the 2013 number of congregations). This certainly isn't enough to warrant all these new congregations. It's not as if large numbers of people are being converted in a local area to the point where new congregations are being formed purely out of new converts.
My speculation is that these are smaller language groups that were formed in years past and that now have been converted over to actual congregations. Other than that, I can't really account for the additional congregations.