Nearly 600,000 employees received a nine-figure salary last year, up 13.3 percent from the previous year, the National Tax Service said Wednesday.

The average salary of employees in South Korea was about 32.5 million won ($26,900)

The increase rate of the number of nine-figure salary earners had reached as high as 42.3 percent in 2010, but the rate has remained at around 10 percent since 2012.

They took up 3.4 percent of the entire workers who had their year-end tax adjusted last year.

By region, workers in Ulsan were paid the most on average, at 41.02 million won, followed by Sejong at 36.79 million won and Seoul at 36.35 million won.

A total of 544,000 foreign workers had their year-end tax adjusted, a 7.1 percent increase from 2014. Their average salary increased by 1.7 percent to 23.30 million won.