This is the final chart I will put up from the 2006 and 2011 Aust census.
What I have done is taken 5 year cohorts from each census and lines them up so that you can see in each age group, how many remained JW's over a 5 year period. Eg, there were 5119 JW's between the age of 15 and 19 in 2006, but in 2011 that same group (now aged between 20 and 24) dropped to 4597. The fourth column is just the difference between columns 2 and 3, for ease of reference.
One of the questions in the 2011 census was in relation to which state or territory you were living in in 2006. The fifth column is the number of those living overseas in 2006. The sixth column is just the 4th col, less the 5th col, for ease of reference.
This data shows the leaving in droves from 15 to 24, and the trickle back in subsequent years. Note what happens in the 5-9 bracket. From 70 onwards, mortality takes its toll.