About half of South Koreans who file tax returns earn an average 1.72 million won ($1,515) a month, data from the tax agency said Thursday, an amount which is just enough to sustain a single temporary worker.

The median income in 2015, is derived by dividing the income distribution into equal halves, compared with a monthly average income of 2.69 million won, according to the data provided by the National Tax Service to Rep. Park Joo-hyun for a parliamentary audit. The records cover the years 2008-2015.

A report in July by the Minimum Wage Commission said a single temporary worker spends approximately 1.75 million won a month on basic necessities.

When only earned income was counted, median income came to 1.89 million won per month and average income was 2.7 million a month.

The latest data reaffirmed the heavy imbalance between the top and bottom earners. The highest 10 percent made an average of 119.74 million won a month, compared to 1.66 million won earned by the lowest 10 percent. In earned income, the top 10 percent made 105.16 million won each month compared to 2.14 million won earned by the bottom 10 percent.

"People's spending becomes more stunted as income is concentrated among high-income earners, a fact that can stagnate economic growth," Park said. "Increasing spending by assisting the low-income group, who are highly limited in consumption capacity, is the only solution to (this problem)." (Yonhap)