Umm, 7 -10 times a week. I might wear two different pairs of jeans in one day.
(OH NO! Is that a fashion crime?) :-0
I am trying to branch out, I just purchased a paisley skirt from J Crew and I'm on the hunt for khaki pants (not jeans).
ETA: In the summer I will wear slightly fewer pairs of denim, as I am more likely to pull out skirts or dresses on extremely hot days. (When even Bermuda length jeans are too hot.) However in the summer it will still average 5 days a week because I wear black Bermudas to work.