U.S. Census Bureau: In the Past 43 Years, Family Households Have Become a Smaller Share of Total U.S. Households, Declining from 81% in 1970 to 66% in 2013

The U.S. Census Bureau report is linked below.

U.S. Census Bureau: Family Households Became Less Common in the Past 43 Years

"Sixty-six percent of households in 2013 were family households, compared with 81 percent in 1970. Family households include two or more people (one of which is the householder) living under the same roof related by blood, marriage or adoption; it does not have to include anyone who is married."

---U.S. Census Bureau, November 25, 2013 Report