(AP photo)

(CNSNews.com) – For the first time ever, the percentage of married households fell below 50 percent, according to the Census Bureau, which released a brief Wednesday about families and households from the results of the 2010 Census.

The percentage of married households fell to 48.4 in 2010, down from 55.2 percent in 1990 and 51.7 percent in 2000.

“The 48 percent of husband-and-wife households in 2010 was the first time since at least 1940 that this has fallen below 50 percent,” said Daphne Lofquist, Statistician for the Fertility and Family Statistics Branch for the Census Bureau.

The Census Bureau did not start keeping detailed statistics about the marital status of householders until 1940.

The new data was released during a conference call briefing with reporters on the “2010 Census Brief: Households and Families.” (See full presentation here.)

All other household categories saw an increase: female householder with other family members living (11.6 in 1990, 13.1 in 2010); male householder with other family living (3.4 in 1990, 5.0 in 2010); two or more people in non-family households (5.2 in 1990, 6.8 in 2010); and one-person households (24.6 in 1990, 26.7 in 2010).

The Census Bureau also re-released data on same-sex households first issued last fall, indicating the total number of same-sex unmarried partner households to be 0.6 percent -- 646,464 out of the total 116,716,292 households.

As CNSNews.com previously reported, the Census Bureau originally had “artificially inflated” the number of same-sex households by nearly 40 percent due to data capturing errors on 2010 Census forms. The Bureau devised a “Preferred Estimate” to more accurately depict the incidences of same-sex households, and relies on this data in its latest report. The number of same-sex households was revised downward from 901,997 to 646,464.

“It is important to keep in mind here that there are several external factors that affect counts for the same-sex partner households,” said Rose Kreider, chief of the Fertility and Family Statistics Branch. “One is that who identifies themselves as a same-sex couple may shift over time.”

“Identifying as a same-sex couple may be more acceptable now than it was in 2000, so that the group who identified themselves as same-sex couples might be a somewhat different group than it was in 2000,” she said.

“And secondly, in the 2010 Census data we had a problem with the non-response follow up form that created some issues in estimates of these households,” Kreider added, as she confirmed that the data used in Wednesday’s brief were from the preferred estimates.

Lofquist said the percentage of same-sex households increased from 0.3 percent in 2000 to 0.6 percent in 2010.

“This is a very small percentage increase,” she said, “however, the total number of same-sex couple households actually increased by 80 percent between the two years.”

The Census Bureau also released data on interracial same-sex couples, finding that 50 percent of these unmarried households are comprised of one Hispanic and one non-Hispanic.

Other highlights from the report included findings of an aging population due to an increase of households with a member 65 years old or older, and a decrease in households with an 18-year-old or younger between 2000 and 2010.

Households with a senior increased from 23 percent of all households in 2000, to 25 percent in 2010, while those with an eighteen year old declined from 36 percent of all households to 33 percent in 2000 and 2010 respectively.

Also on the rise are people living alone. 31.2 million households consisted of one person living alone—27 percent—according to the report. This represents a one-percentage point increase since 2000.

Kreider said the data is consistent with the ongoing trends seen in recent Censuses, which are taken every 10 years.

“What we’re seeing is a continuation of trends that we had already seen for quite awhile,” she said.

The number of married Americans declined steadily over the last several decades, according to a study by the Pew Research Center last year. A report released on Dec. 14 found that the number of adults currently married hit a record low of 51 percent.

By contrast, in 1960 72 percent of adults 18 or older were married. “If current trends continue,” the study stated, “the share of adults who are currently married will drop to below half within a few years.”

“Other adult living arrangements-including cohabitation, single-person households and single parenthood-have all grown more prevalent in recent decades,” it added.