A retired police officer, who wished to be identified by his last name Park, 63, believes “60 is the new 40.”

“After retiring from my job I started watching over kids as a ‘school sheriff’ at an elementary school nearby. I just was not used to staying at home without a job,” Park told The Korea Herald.

Last month, the number of overall employed workers increased by 310,000 on-year, and this rise was largely led by workers like Park, who are in their 60s, according to Statistics Korea data on Sunday.

The number of employed individuals aged 60 and over in February stood at 5.77 million, seeing an increase of 413,000 on-year. This is the highest figure for February since the statistics were first compiled in June 1999.

This data also showed that the number of employed workers in their 20s and younger and 40s decreased by 125,000 and 77,000 on-year respectively.

The upward trend in the number of working older adults is also evident when looking at the data for the last two decades.

In February 2003, there were 1.85 million workers who were in their 60s. The figure jumped to 2.73 million in February 2013 and over the last 10 years, it more than doubled to 5.77 million.

Also, last month, the employment rate for those aged 60 and over was recorded at 42.8 percent, up 1.5 percentage points on-year.

This is the highest figure for February since the statistics were first compiled in July 1982.

However, the employment rate for the youth population -- aged between 15-29 -- decreased by 0.4 percentage point from the same period last year to 45.5 percent.

The surge in the number of working older adults is partially due to Korean baby boomers -- those born between 1955 and 1963 -- entering their 60s.

In February 2003, the number of individuals in their 60s was 5.8 million. In February 2013, it increased to 8.34 million, and in February this year, it reached 13.49 million.

Many of those in their 60s continue to work due to financial reasons.

In a report released by the Bank of Korea in October last year, it stated that the increase in the employment rate of older adults is mainly due to economic factors -- such as a decrease in financial support that they get from their children, a sharp increase in living expenses compared to the amount that they receive as public pensions and asset income --as well as improvements in health condition.

The tendency for those 60 and over to enter the labor market to earn money is also reflected in the results of a Statistics Korea survey conducted in July last year.

According to the survey, the percentage of those aged between 55 and 79 who hope to work in the future increased significantly from 59.2 percent in 2012 to 68.5 percent last year.

On average, they wished to work until they are 73.

The survey also showed that more than half of those polled wish to work because they want to pay for their living expenses, while 34.7 percent want to work because they are still healthy enough and find joy in working.