Teen pregnancy rates plummet.

A new report from the Centers for Disease Control and Prevention (CDC) reveals that teen birth rates in America have fallen by 57% since 1991. The primary culprit? Contraception.

Image Credit: CDC

As Slate notes , the CDC cited a paper from the American Journal of Public Health, which found that 86% of the drop in teen pregnancies between 1995 and 2002 came from an increase in contraception use. And the more contraception, the better, as far as the CDC is concerned. Using a dual method is "especially effective in reducing repeat births among teenagers," it stated in the report.

Putting things in perspective: The decline in the birth rate corresponds to 4 million fewer babies born to teenagers between 1992 and 2012. It also saved taxpayers a whopping $12 billion alone in 2010, as the cost of raising a child is unbelievably expensive and even more so for teen mothers.

Image Credit: USDA

It's not just one group, either. The report states that the drop in the birth rate is true across all age groups, races and states. Incredibly, fewer children are born to teen mothers now than in 1950, when, as Slate's Jordan Weissman writes, the country's population was less than half what it is now.

However, there are some differences across states. And they're just what you would expect. Take the following map, which shows states where sex ed classes must include abstinence-only education, but not information about contraception:

Now take a look at the CDC's map of states where teen birth rates are the highest:

Image Credit: CDC

The pattern is clear: States with abstinence-only sex ed policies tend to have higher teen birth rates. It's yet another indication that teaching teens about contraception and smart sex prevents them from getting pregnant.

And people are still trying to prevent it. Despite the sharp decrease in teen pregnancy, the rate in the United States remains higher than in most developed countries. That's partially because the state of sex and contraception education is so dismal. Even more worryingly, legislators are still trying — and often succeeding — to defund them.

Advocates say abstinence-only education is the only true way to prevent teen pregnancy. But as the CDC study shows, that's simply not true. We can only hope that access to contraception remains intact; otherwise, those declining rates may not continue.