Teen pregnancy and abortion rates have reached a "historic low" in the United States since they peaked back in the 1990s.

In 2010 there were about 614,000 pregnancies in women between the ages of 15 and 19; that translates to 57.4 pregnancies for every 1,000 women in this age group, a Guttmacher Institute news release reported.

This shows a 51 percent decline since 1990 and a 15 percent decline over the past two years.

There was a significant drop in pregnancy rates in women between the ages of 15 and 17 as well as in the 18 to 19 range between 2008 and 2010, but pregnancies in 18 and 19 year olds made up a 69 percent majority.

"The decline in the teen pregnancy rate is great news," lead author Kathryn Kost said in the news release. "Other reports had already demonstrated sustained declines in births among teens in the past few years; but now we know that this is due to the fact that fewer teens are becoming pregnant in the first place. It appears that efforts to ensure teens can access the information and contraceptive services they need to prevent unwanted pregnancies are paying off."

The team found a decline in teen pregnancy within racial and ethnic groups as well. The pregnancy rate fell 56 percent among non-Hispanic white and black teens between 1990 and 2010. The rate declined by 51 percent in Hispanic teens between 1992 and 2010. Teen pregnancy rates are still twice as high in black and Hispanic teens as they are among white teens.

The rates are on the decline in every U.S. state, but there are still disparities. In 2010 New Mexico had the highest teen pregnancy rate at 80 per 1,000 women. Other states with high teen pregnancy rates include: "Mississippi (76), Texas (73), Arkansas (73), Louisiana (69) and Oklahoma (69)," the news release reported.

The lowest rates were found in "New Hampshire (28 per 1,000), Vermont (32), Minnesota (36), Massachusetts (37) and Maine (37)," the news release reported.