Amid an economic slowdown and a growing preference for experienced hires, securing a job in one’s 20s has become increasingly difficult in Korea, raising concerns about the prospects for younger generations.

The proportion of employees in their 20s at Korean companies dropped below that of workers aged 50 and older last year, according to data released Monday by corporate tracker Leaders Index — the first time such a reversal has occurred since the survey began in 2015.

Experts say the aging of corporate workforces is a trend that will continue, and likely accelerate due to demographic shifts.

“It’s only natural that workers in their 50s are becoming the majority,” said Yoon Dong-yeol, a business professor at Konkuk University. “We can’t ignore the rapid population aging driven by the country’s low birthrate.”