PORTLAND, Ore. – Data released Thursday by the U.S. Census Bureau shows married couples have found themselves in a new niche: They’re no longer the majority.

It’s a trend that’s been creeping along for decades, but in the 2010 Census, married couples represent 48 percent of all households. That’s down from 52 percent in the last Census and, for the first time in U.S. history, puts households led by married couples as a minority.

The flip in the 2010 Census happened in 32 states. In another seven states, less than 51 percent of households were headed by married couples.

The reason, said Portland State University demographer Charles Rynerson, is twofold: The fast-growing older population is more likely to be divorced or widowed later in life, and 20-somethings are putting off their nuptials for longer stretches.

Fears of not being able to hang onto a job, a widening labor market for women and a shift away from having kids at a young age have all proved to be a disincentive for people in their 20s and early 30s to join the ranks of the married.