With all the talk of eroding family values and news of severed celebrity marriages, you may find it hard to believe that the U.S. divorce rate has actually been declining since its peak in 1981. That’s right – the national rate of divorce is now at its lowest level since 1970, the same year “The Partridge Family” debuted on TV and “Let It Be” topped the pop charts (and about the same time The Beatles cited their own irreconcilable differences). Behind this trend is the fact that more Americans are waiting to tie the knot – on average five years longer than back in 1970 – and many aren’t marrying at all. Even when they do meet Ms. or Mr. Right, many couples are choosing to live together unmarried for the long-term, resulting in ten times the number of Americans co-habitating or “shacking-up” compared to 1960 levels.