With the smaller percentages sample size becomes a big problem with JWs. Wouldn't take too much note of increase in college degrees, and the question which indicates some JWs are 'living in sin' would suggest a very broad sample base to say the least.
The broader trends are interesting. It's a religion which actively sets out to guilt trip people over having a well paid job and for being financially secure - while offering televised productions of the perfect family, in the perfect home, living on whatever income a couple of pioneers can scrape together.