The number of subscribers to the national pension scheme will peak next year and begin to shrink from 2019, due to the aging of the population, according to a new projection.

The state-run National Pension Service said that the subscriber tally will reach its highest at 21.93 million next year from this year’s 21.89 million. In 2019, the figure is expected to fall to 21.91 million.

By 2021, the number will be down to 21.7 million.

The number of pensioners, on the other hand, is forecast to increase from 4.78 million in 2018 to 6.07 million in 2021.

NPS’ data is based upon the Statistics Korea’s projection on the economically active population here. The total number of Koreans aged 15-64 will start decreasing this year to account for just 47.0 percent of the total population by 2065. In 2015, it took up 73.4 percent.

Decreased membership means a drop in the rate at which the fund’s revenues increase, according to the data. The rate is expected to stand at 3.45 percent in 2018 and to fall to 2.79 percent in 2021.

“The projections reveal that amid a decrease in the number of the working population and low birth rate, the fund would run out much faster than (previously) expected,” NPS’s public relations director Yoon Young-seok told The Korea Herald.

The total fertility rate, or the number of children born per woman, remained at 1.25 last year, the lowest among the 35 member countries of Organization for Economic Co-operation and Development, according to the CIA’s World Factbook.

The pension fund, managed by the NPS, meanwhile, is expected to grow in size from 600 trillion won at the end of 2017 to 789 trillion won in 2021, thanks to increased premiums to be collected as workers receive more salaries in line with the inflation rate.

By Bak Se-hwan (sh@heraldcorp.com)