Women are waiting longer before getting married - if they get married at all, according to a new analysis.

The U.S. marriage rate is now at 31.1 - which in statistical terms means roughly a rate of 31 marriages per 1,000 married women, not 31 percent. That rate is 60 percent lower than 1970. In 1920 the marriage rate was 92.3. The wave of gay marriage legislation across the US will likely cause a temporary blip in that, at least until expensive gay divorces kick in, but the overall trend will remain downward.

The new Family Profile from the National Center for Family and Marriage Research (NCFMR) at Bowling Green State University, "Marriage: More than a Century of Change," used data from the National Vital Statistics "100 Years of Marriage and Divorce Statistics United States 1867-1967," the Centers for Disease Control and Prevention/National Center for Health Statistics, and the U.S. Census Bureau, and also finds that a woman's average age at first marriage is the highest it's been in over a century, at nearly 27 years old.

"Marriage is no longer compulsory," said Dr. Susan Brown, co-director of the NCFMR. "It's just one of an array of options. Increasingly, many couples choose to cohabit and still others prefer to remain single."

"The age at first marriage for women and men is at a historic highpoint and has been increasing at a steady pace," states Dr. Wendy Manning, co-director of the Center.

There has also been a dramatic increase in the proportion of women who are separated or divorced. In 1920, that was less than 1 percent of women. Today, that number is 15 percent. "The divorce rate remains high in the U.S., and individuals today are less likely to remarry than they were in the past," reports Brown.

The marriage rate has declined across all racial and ethnic groups but the greatest decline is among African-Americans. There is also an education divide in marriage. In the last 50 years there have been only modest changes in the percentage of women married among the college educated and the greatest declines among women without a high school diploma.