Nearly 600-thousand South Korean workers were found to have earned more than 100 million won, or roughly 83-thousand U.S. dollars, in annual salary last year. That's according to the National Tax Service's annual tax report released on Wednesday. 

The report found that South Korean workers earned an annual average of some 32-and-a-half million won in 2015.

The tax agency looked over year-end tax adjustments of some 17-point-three million wage earners and found that 596-thousand earned more than 100 million won last year. That's up more than 13 percent from a year ago. 

The number of foreign workers who completed a year-end tax settlement stood at 545-thousand, up some seven percent from a year ago. Such workers earned 23-point-three million won on average last year, up one-point-seven percent from 2014. 

Out of the foreign workers who completed year-end tax settlements, Chinese nationals amounted to some 197-thousand, accounting for the largest groups of foreign wage earners.