The number of employed women in their 20s plunged by 26,000 in May compared to the same period a year ago, Statistics Korea said Monday, the biggest drop of any group.

This contrasted starkly with an increase of 139,000 employed women over 60 and 107,000 among women in their 50s over the same period, although far fewer jobs are available in the older age groups.

The reason is that more and more older women look for work to make ends meet in tough times.

According to Statistics Korea estimates, the female population is expected to reach 25.3 million and outnumber the male population in 2015. But there is still a dire shortage of quality jobs for women.

In metropolitan areas, where there is a high concentration of university-educated workers, employed men far outnumber women with jobs -- 61,3 percent versus 38.7 percent in the first quarter of the year. And the figures rose 0.6 percentage points on-year for men but fell as many points for women.

Also, 63.3 percent of employed men had regular jobs with monthly salaries, compared to only 36.7 percent of women. And the so-called economic participation rate of university-educated women was 63.3 percent, as against 89.3 percent of men in the same educational bracket.