CNN reported in Divorce Rates Falling, Report Finds just what the title states. I wondered before reading the article if it's because people typically live together first before marrying; therefore, if they do decide to marry later, they're more sure about it, and they end up sticking together. That's basically what the article said, but I've also heard that people who do live together, have the "test the waters" mindset and tend to continue to "test the waters" with people other than their spouse after marriage. Maybe things have changed though; who knows.
<sarcasm> I do know, however, that female and male bodies are meant to fit together; people have been proving this for thousands of years successfully (post-marriage). </sarcasm>
On a related note, LAF/Beautiful Womanhood just linked to an article today stating that Kids Can Do Abstinence, Data Shows.