If you're referring to the archives at Google Groups...
They (Google) changed the way they show a posters past activity. It sucks
compared to the way it used to be. It used to show a nice "chart" with
activity count by year and month.
I try to respond to at least 300 questions per month (I'm sure I could
double that if all I was interested in was obtaining a "post count"). I used
to rely on Google's reporting to see if I was meeting my self-imposed quota.