Of the 72 million fathers in the United States, 66 million either have been or are currently married, according to the first U.S. Census Bureau report to provide a detailed demographic profile of fatherhood.

Released today, the Men’s Fertility report shows that only 6 million fathers have never married.

Nearly 3 in 4 fathers are currently married (73.4 percent), 12.9 percent of fathers are divorced, 3.2 percent are widowed, and 2.3 percent are separated.

The remaining 8.2 percent of fathers have never been married.

Among men aged 30 to 34 who are or were married, 72.8 percent have a biological child.

By comparison, 26.3 percent of never-married men of the same age have a biological child.

Men who have never been married also tend to have fewer children than those who are currently or previously married. That is due in part to the fact that they are younger, on average. 

Nearly a third of men who are or have been married (31.7 percent) have three or more children, compared to just 3.1 percent of never-married men.

These data come from the 2014 Survey of Income and Program Participation, which collects detailed information about U.S. families’ economic well-being.