3646 new posts / month
153 new members / month
of course i could've just got the averages by dividing the totals of posts / members by the total of months (40 months), which is probably more accurate, but that'd be too simple and easy
but if you're curious, that'd give you:
2456 new posts / month
110 new members / month
i also did some other thingies in excel, like some charts and pointed down Most Users Online and Forum Version along the "snapshots" in Archive.org. there's a screenie.