How fast does hair grow ?

i'm 19 yr old asian guy and have medium hair length, but i want the Zac Efron hair look. How fast does hair grow? I don't smoke, drink, use any irons or anything to style my hair. i wash my hair only once a week..I'm starting to notice my hair falling out everyday... what can i do to enhance the growth - i WONT trim my hair because this will delay the growth of my length...