GMail spams surprised me

I was quite used to delete gmail spams every hour or so. Later I thought how come google didn't do anything to reduce the spams ( i was getting very few in hotmail 3/4 per day at max). I decided to gauge the gmail spams and not to delete any spams from Oct 26, 2006. I wonder if google knows about my plan but 5 days after I started, the spam decreased to 1 per day. I don't know whether I mis-seen, but I felt that I have seen 3 spams on Oct 31 but later there was only one. Well google wouldn't delete fresh spams automatically. Maybe my mistake.

Here's the 6 days result

Oct 26: 16
Oct 27: 13
Oct 28: 13
Oct 29: 9
Oct 30: 15
Oct 31: 1 (this one really surprised me)

I will continue for entire November month. That will be a better measure.