The number of years a woman over the age of 30 appears to be relative to her actual age... signified by age lines and a marked decline in willingness to do anything resembling fun. Generally a ratio of 3:1 over actual age. (Ex.: 35 actual years old equals about 105 chick years)
Dude 1: "Hey, brah... how old is your girl's friend there? She's hot!"
Dude 2: "She's 36"
Dude 1: "Oh, fuck that... That's like 108 in chick years..."
Dude 2: "Word."