You could email Bishop (PMs aren't answered very quickly) and I'm sure him, or someone else can get back to you on that. Maybe shoot MacMahoooon or BigJim a PM, those guys check daily, and they can let Bishop know so he'll answer you quicker.
I don't know many stats but I can tell you there is an average of 24 replies per thread in NSG and 21 in SG. and out of the 290849 total threads made on NS (at least after the recode in 01 I think) there is an average of .05 replies per thread. Actually I probably did that math wrong with my cell phone calculator but whatever, there's 5466934 total replies. Hope that helps