Confirming occasional research from the past five years, the U.S. Census Bureau released data today that said less than half of American households are headed by married couples and only 20 percent are composed of what is often considered the mainstream—“married with children.”

William Frey, a senior demographer at the Brookings Institution who analyzed the data, told The New York Times, “The days of Ozzie and Harriet have faded into the past.”

Unmarried couples made up 12 percent of U.S. couples in 2010, a 25 percent increase in 10 years. Two-thirds of the cities with the largest shares of unmarried couples were in the Northeast and Midwest, up from about half a decade earlier.