The number of South Koreans aged 100 and older soared to top 3,000 last year as the country is rapidly heading to an aged society, government data showed Monday.

A total of 3,159 centenarians were living in the country whose total population amounts to 50.62 million as of November 2015. The number is up from 1,835 tallied five years earlier, according to the census data compiled by Statistics Korea. Among the centenarians, 2,731, or 86.5 percent, are female.

Their secret to living a long life is healthy eating habits, such as light eating, a well-regulated lifestyle and optimistic attitude, according to the data.

The nation’s aging population and low birthrate are raising concerns over a decrease in the working-age population.