I have updated the articles at http://www.jwfacts.com/watchtower/memorial-partakers.php and http://www.jwfacts.com/watchtower/statistics.php with the latest figures. After slimboyfat's comment on congregations, I have included a graph on congregation growth. This does move in line with publisher growth rates, though at a lower figure, as the average number of publishers per congregation has grown from 50 to 68 over the last 50 years.
I particularly like the following graph, as it shows what an incredibly small number of bible studies progress to baptism.
Whilst JWs feel it looks great how much hours of preaching continue to grow, baptisms have fallen from their peak 20 years ago, so this is becoming more and more ineffective.