Related Posts: Growth of the Church (2007)
Summary: Is the growth of the church decelerating? I would have to say no. First, the acceleration the church experienced from 1950 to 1990 was small. Only 6,290 persons per year^2. So a change is not too surprising. From 1991 to 2013 there appears to be a very small deceleration, but this can be said with only 63% confidence. In other words, there is a 37% chance the apparent deceleration is not real. Otherwise, the growth rate is constant.
If we look at convert baptisms the number in 2013 is about 8,500 higher than in 1992. And for the last eight years has been fairly constant at about 275,000 per year. Non-convert baptisms is holding steady at 46,000 persons per year.
Baptisms per missionary have decreased due to a fairly constant conversion rate combined with a dramatic increase in missionary force.