@Stillin the world average annual population growth is just above 1% I think I read 1.14 %, it is declining and will be 1% by 2021.
The JW increase in publishers has been about 2.5% but remember the “world average” is not the same demographic as JW membership which includes a lot of nations with higher numbers of children than average, especially in South America and central Africa. So it would be expected to produce new JWs at above the world average of population increase by insider births alone. It seems that the % increase is in line with JW births of born-ins based on this demographic.
But half the number of all new Witnesses go missing each year through deaths, DF and faders so there is probably another group of new converts coming in to make up some of the losses especially in Brazil where they don't take the JW religion too seriously and also in the politically unstable parts of tropical Africa where historically JWs have always flourished.