The small number of Americans – around 55,000, or 0.02 percent – who make it to their 100th birthday are less educated, poorer, and less likely to be veterans than the country’s much-larger 65-and-older population, a new Census Bureau report shows.

A large part of the differences seems to be attributable to the fact that women live longer than men; the findings, therefore, provide a more comprehensive snapshot of centenarian women. Most centenarians – 81 percent – are women, according to the report, “The Centenarian Population: 2007-2011,” which was released Wednesday and is based on 5-year data from the American Communities Survey.

In the past three decades, the population of centenarians in the United States has increased by 66 percent, almost twice the rate of the total population, according to a 2012 Census report.

Still, centenarians are “a very small and rare group,” said Brian Kincel, the report’s author. “They are distinct from the rest of the older population.”

Most of them – 82 percent – are widowed; 17 percent live in poverty, compared to 9 percent of people 65 and older.

Among the generation of people born before World War I, women typically earned less money and were less likely than their male counterparts to serve in the military compared to later generations.

While some of the same trends appeared in the 65-and-over population, which is 57 percent female, they were less pronounced. More of them are married than widowed, although the married and widowed rates for women are equal at 41 percent.

But among people who have lived 100 years, one thing is equal among genders: high school graduation rates were lower for both men and women. Forty-three percent of today’s centenarians did not get a high school diploma or GED, while for the 65-and-over population, that number dropped to 23 percent.