An average income earner who pays into the national pension for 30 years would still get far less in return than what he or she needs for the most basic sustenance in senior years, data showed Friday.

A worker who makes 2.18 million won ($1,924) a month, the average income as of 2016, would receive a monthly 670,000 won after a 30-year subscription, far short of the 1.04 million won needed to meet basic needs, according to the data released by the office of Rep. Nam In-soon. The figures were derived from the National Pension Service (NPS) records provided to the lawmaker for parliamentary audits.

National Pension Service Investment Management (Yonhap)

Data showed that a subscriber would have to earn at least 4.34 million won a month, categorized as top-level income, and stay subscribed for 30 years in order to reach the minimum amount needed for senior life.

According to separate data from the Ministry of Health and Welfare, an average pension subscriber as of this year was enrolled for just 17 years, meaning they receive much less than the estimated amount. For instance, people making average income and who paid into the pension for 20 years would only get 450,000 won.

South Korea's aging society has put a strain on the NPS which is saddled with growing payment needs. The nominal income replacement ratio for 40-year enrollment was as high as 70 percent in 1988, but it fell to 60 percent in 1998 and a further to 50 percent in 2008. By 2028, it could go as low as 40 percent. As of this year, the ratio stood at 45.5 percent.

The rate for an average subscriber enrolled for 17 years would stop at 24 percent.

"We have to increase the amount of pension input at a reasonable level through social consensus on the principle that appropriate payment should be commensurate with appropriate benefits," Rep. Nam said. (Yonhap)