US marriages last longer than unions where couples live together outside matrimony, the Centers for Disease Control reported on Tuesday.

美国疾病控制中心本周二发布报告称，美国的婚姻关系比非婚同居关系维持得更为长久。

Newlyweds kiss after getting married atop the Empire State Building in New York February 14, 2006.

About 78 percent of marriages lasted five years or more, compared with less than 30 percent of what the CDC called cohabiting（同居） unions, or couples living together outside marriage.

One reason cohabitations were shorter-lived than marriages is that 51 percent of couples who lived together made the transition¹（过渡，转变） to marriage within three years, CDC said in a statement.

Over 40 percent of men and women aged² 15-44 were married in 2002 when the interviews were conducted, compared with 9 percent who were living together. The report was based on a nationally representative sample of 12,571 men and women.

Other findings:

The odds³（机会，可能性） of staying together 10 years or longer in a first marriage are better for couples of the same racial origin, the report found.

Nearly 80 percent of couples who have their first child at least eight months after their first marriage are likely to celebrate their 10th anniversary; those who don't have children are more than twice as likely not to last 10 years.

About 75 percent of marriages between men and women 26 years old or older last at least 10 years, compared with only about half of teen marriages.