Teen birth rates are at a historic low. The National Center for Health Statistics says the number of births to teens between 15 and 19-years-old last year was about 275-thousand.

That's the lowest number since the agency began tracking data from all states in 1933. It's also less than half of the all-time peak, which was recorded in 1970 with roughly 645-thousand teen births.

A spokesman for the National Campaign to Prevent Teen and Unplanned Pregnancy calls the drop "almost unbelievable." (Metro Networks Inc.)