Has your community size grown steadily?

Hey all.

I've got a question to ask - has the size of your forum increased at a steady rate, or have there been spikes and bumps along the way? On my forum, which is rather small but growing day by day, we have very irregular rates of posts and new topics - one day 70 posts may be made but the next only 5. Is this normal for a forum of this size (around 2000 posts, with 37 members), or should the post rates be more steady?