Photo courtesy of Janine via Flickr, modified by Curiousmatic.

For the first time in decades, nonmarital birth rates in the U.S. are declining. Teen birth rates are oddly much lower, even as overall birth rates have leveled off since the recession.

A new report from the National Center for Health Statistics, which analyzes birth rates between 2002 and 2013, finds that birth rates are down 7 percent and nonmarital birth rates down 14 percent since peaking in the 2000s.

Interestingly, though 4 in 10 births have been to unmarried women since 2007, the demographics, ages, and circumstances of which children are born to unmarried women is changing, more frequently occurring within cohabiting unions, and much less among teens.

Here are some of the key findings, and what they indicate, according to the study.

1. The number and rate of nonmarital births has declined since a peak in 2008.

Both birth rate and number of births has increased significantly over time, in 2013, rates were the lowest since 2005, and seven percent lower since the all-time peak in 2008.

Though rates and numbers have fallen previously, the current is the steepest decline in the timeframe studied.

2. The declines were evident for all age groups, except among women aged 35 and above.

Since 2007, births among unmarried teens, twenty-somethings, and even those in their early thirties have declined. But births among older age groups, in contrast, have risen.

The birth rate among unmarried young people aged 24 and younger have fallen to lower numbers than 2002. It’s the historically low birth rate among teenagers specifically, however, that has researchers stumped–some statisticians even thought it was a mistake initially.

Many suspect that the decline among teens (to a rate lower than the 1940s) is due to a combination of factors such as decreased sexual activity, better sex education and contraception, and economic recession.

3. The sharpest decline among nonmarital births was for black and Hispanic women.

As the graph indicates, nonmarital birth rate has all but fallen back to its 2002 level overall. And though black and Hispanic women account for the largest share of nonmarital births, both of these demographics have dropped sharply to below their 2002 rate–that’s a 27 percent decline since 2007 among Hispanic women, and 11 percent among black women.

4. Nonmarital births were increasingly likely to occur between cohabiting unions, and about the same among couples intending to marry.

A comparison between 2002 and 2006-2010 shows that in the latter, 58 percent of nonmarital births are born to couples living together, as opposed to just 41 percent in the former. About the same percentage of mothers were intended to marry in both time brackets; in the more recent timeframe, half of couples living together were also engaged to marry.

Though the CDC notes that the relationships of cohabiting couples are generally less stable than marriages, they find their data suggestive of higher levels of social and financial support within unions — especially since a similar report (pdf) has found that cohabiting fathers were involved in family life on similar levels as their married counterparts.

5. The share of nonmarital births in America still, on a whole, slightly outweighs its European counterparts.

Pew research finds that when comparing 2011 numbers, nonmarital births for Europe on a whole account for 39 percent of births, while America’s account for 41 percent.

On a broader level, the share varies dramatically across European nations: in Iceland, 67 percent of births are nonmarital; in Turkey, only 3 percent. On a global level, it’s an even greater disparity, with 87 percent of births nonmarital in French Guiana, and less than 1 percent in Bahrain, Kuwait, and Qatar.

The United States falls around the middle, and whether it will continue to fall further remains a mystery (some believe it will follow overall birth rate and level off as the economy improves).