SBF - [The book author]...says that getting access to the more detailed information in census returns can be tricky even for academics, and expensive. It should be possible to get the figures for earlier censuses and track JW education over time. But it might cost to access the information and the information might be difficult to extract.
A couple of years ago, I got passwords for the 2006 and 2011 census databases. (All legit.) This was before I joined this forum. I downloaded a fair bit of data, but it is a more complicated task than it sounds, for reasons I wont go into. (It is probably expensive, because it is time consuming, and will do your head in.)
I had planned to do it again once the 2016 census data was available, and produce a comprehensive report on the status of the cult in Aust, but I am not sure I will be able to. Given this thread, I will add a few snippets of what I have, even though it is old data (2006 and 2011). I will do so in subsequent posts.