!20/80 is considered normal. Your reading is pretty good. High is 140/90 and low is 100/70.
I was just at the doctor today and mine was 100/70... last year at this time it was like 92/68 or some bizarre number like that... I was doing 2 hours of cardio a day w/some occasional lifting (nothing even worth mentioning really) and was undereating a lot at that time, especially for my activity level.