The teen birth rate keeps dropping.

A government report says that last year teen pregnancies hit a record low, falling by 8 percent.

The rate last year fell to 22.3 births per 1,000 teenage girls aged 15 to 19, down from 24.2 births in 2014, the U.S. Centers for Disease Control and Prevention said in a preliminary study based on birth certificate data. The birth rate for teenagers has dropped 64 percent from its peak in 1991, the agency says.

Experts say it's because teens are having less sex, have positive peer influences and are using more birth control.