The following figures are from the Australian Census 2006 as found at http://www.abs.gov.au/websitedbs/d3310114.nsf/Home/census (30th June 2007).
Very interesting to see that the number of people admitting to being Jehovah's Witnesses has fallen over the last 10 years by 3%, whilst Baptists have grown by 7% and Mormons by 18%. Looks like JWs are not the only ones preaching afterall.