South Korea's working age population is forecast to decrease much faster than other members of the Organization for Economic Cooperation and Development(OECD).

According to the Korea Institute for Health and Social Affairs on Tuesday, the population of OECD members aged between 15 and 64 is projected to decrease by one tenth of a percent on average over the next 20 years. 

However, the comparable figure for South Korea is predicted to be 18-point-nine percent. 

The institute said that OECD members are expected to witness decreases only in their populations aged under 40, but South Korea will see a drop even in the population of those in their 50s. 

The country's working age population posted its first drop last year after reaching a peak of 37-point-63 million in 2016.