Wow....the numbers are very telling but of course JW's will put the decrease in number, down to the fact that the preaching work is nearing the end and only "sheep like ones" in developing nations are remaining. However, to say that is also to say that it is a foregone conclusion on their part, that young ones and newborn children in western lands, won't ever accept "the truth".
(I've reposted the Graphic in a smaller form because for some, the original version may have been too large to see.)