Is your adult son living in your basement? Consider yourself part of a trend.

The U.S. Census Bureau reports in a new study that the percentage of men age 25 to 34 who are living in their parents' home increased from 14 percent in 2005 to 19 percent in 2011.

It might seem natural to blame the tough economy for the trend, but the Census Bureau says that's not the case.

"The increase in 25- to 34-year-olds living in their parents' home began before the recent recession and has continued beyond it," said Rose Kreider, a family demographer with the Fertility and Family Statistics Branch of the Census Bureau.

The trend is even more dramatic for younger age groups.

The study reported that 59 percent of men and 50 percent of women age 18 to 24 reside in their parents' home in 2011, up from 53 percent and 46 percent in 2005.

The figures included college students living in a dorm.

Other key findings of the study:

-- The percentage of households that contain just one person has risen steadily for 50 years -- from 13 percent in 1960 to 28 percent in 2011.

-- Of the 74.6 million children under age 18, 69 percent lived with two parents; 27 percent lived with one parent and 4 percent lived with no parents. Of the one-parent children, 87 percent lived with their mother. Of the no-parent children, 57 percent lived with a grandparent.

-- Of the 67.8 million couples of the opposite sex who lived together, 89 percent were married. There were about 7.6 million unmarried couples living together.