Maybe you're just not naturally hairy. I'm 22 and am not that hairy besides the usual areas but more and more chest hair seems to appear every year. Besides the immediate pubic areas, body hair may start to appear later on in life, into your thirties. I wouldn't be too upset anyway. A lot of people like a body that isn't too hairy.

The amount of body hair you develop is hereditary. Some people are just prone to more hair. Not much you can do about genetics.