All states but West Virginia and North Dakota showed significant drops over five years. But the Mountain States of Arizona, Colorado, Idaho, Nevada and Utah saw rates fall by 30 percent or more.
In 22 states, teen Hispanic birth rates plunged at least 40 percent, which was described as "just amazing," by the report's lead author, Brady Hamilton of the Centers for Disease Control and Prevention.
What's driving the declines? No one can say for sure. Experts believe the explanation is complicated and probably varies a bit from state to state. The national figure has been falling since 1991, aside from a brief interruption in 2006 and 2007.
The CDC report released Thursday is based on birth certificates for 2007 through 2011. Last year, the CDC announced the overall improvement in teen births: a record low of 31 births per 1,000 teens ages 15 to 19. That compares with 42 births per 1,000 five years earlier.
Image: United States map, via Shutterstock