The U.S. has added fewer new households in 2010 than at any other time within the last 30 years, according to recent Census Bureau estimates. The increase of 357,000 households represents only 0.3 percent compared with an average of 1.2 percent. Numbers have been declining since 2008.

However, the U.S. population has grown by 0.9 percent between 2008 and 2009.

A number of factors contribute to this decline including younger generations struggling in the job market and live with their parents; older generations, including many Hispanics, who live with their children or grandchildren for both cultural and financial reasons; and the increased numbers of unwed couples living together.

Among unwed couples, the number of both partners working dropped nearly 10 percent since 2008 to just under half. Only 76 percent of the men in these couples reported working in 2009, down 10 percent from the number of men in new 2009 couples.

Of existing couples, 40 percent of the men are 45 and older. Of the newly formed couples, that number drops to 26 percent. The percentage of those under 30 climbs from 23 percent to 37 percent. The figures for women in the relationships show corresponding shifts. The numbers of couples where both partners are black nearly double from 6.8 percent to 11.4 percent, when looking at the differences between existing and new couples.