The pool of people making it past their 80s and 90s and well into their 100s has been growing in the past few decades. And even though women have historically proven to live longer lives, the number of men reaching past 100 has been increasing, too.

According to the Census Bureau, the centenarian population in the U.S. has increased by 65.8 percent in the past thirty years. There were over 32,000 people ages 100 and over in 1980; in 2010, over 50,000 people lived past 100.

England and Wales has seen a 33 percent increase of the number of people living past age 90. There are about 453,000 people living over age 90, and up to 12,320 people over the age of 100.

And it’s the females who tend to reach 100. In 2010, some 82 percent of centenarians were women. In the U.K., less than one in ten people in the 105+ age group are men. The rest are all female.

“We know that women are more social than men,” Gary Small, professor on aging and director of the UCLA Longevity Center, told U.S. News & World Report. “If you are social, it may reduce stress levels because you can talk about your feelings and things that stress you out… If you need a ride to the doctor or you fall, they can take you to the hospital.”

The majority of centenarians live with other people rather than on their own, usually in nursing homes. And a large number of America’s oldest surviving people live in cities. In 2010, 85.7 percent of people over 100 were living in urban areas.

“Living in the city, you have a lot more mental stimulation and the symphony and better doctors… and more social networking,” Small told U.S. News & World Report. He also mentioned better resources and access to transportation, as other reasons why city-living may be beneficial for older people.

Meanwhile, Japan has the highest number of old people living than any other country – with 1,197 people over 90 for every 100,000 citizens – followed by Sweden, Italy, and France. The U.S. is 10th on the list.

Various studies have explored the possible reasons behind people living to 100 or more. Isolation, for example, can have a negative impact on one’s health. The Longevity Project, a book chronicling a study of 1,500 people over eight decades, found that religious women tended to live longer, likely due to the social connection they experienced through their faiths. And those who worry to a moderate extent — everything in moderation — lived longer than those who had negative attitudes, a constant sense of dooming failure, and a tendency to be self-critical, according to Leslie R. Martin, the author of The Longevity Project.

Research has also linked walking to longevity; people who walk more and at a faster gait are more likely to live longer than those who do not walk as fast, according to a University of Pittsburgh study.