Based on the figures shown via the Questions and Users links, it seems that there are 2,575 questions, and 4,652 users.
I head Joel Spolsky (co-founder of Stack Overflow) talking about how, in general, people prefer(?) to answer questions than to ask them.
I would think that it's because; the more you know, the less you need to know (of what can be gleaned from a single point-specific question/answer).
However, an average of 0.55 questions per user surprises me.
Are the totals correct?