Number of users who made their first (or last) post or comment on the site in the given month. Take care interpreting this chart: recent months will naturally show large numbers of users last
active. This doesn't imply they permanently left the site.
Registered users (shaded area) completed the signup process. Users (lines) made at least one post or comment on the given site. User ID numbers (not shown) are much higher, because the site allocates an ID number for incomplete
signups.
Number of posts divided by number of users who posted or commented at least once in the month. 1999 and 2000 are
excluded so later years are readable. September 1999 saw 20 posts per user.