The National Health Insurance Service recorded a 4.6 trillion won ($4.1 billion) surplus in 2014, with its annual revenue climbing 7.4 percent from the previous year to reach 48.5 trillion won.

Some of the reasons for the increased revenue include a rise in the number of cancer patients who were diagnosed at an early stage through health examinations, and a significant decrease in the number of patients suffering from respiratory diseases.

Yellow dust storms ― influxes of dusty air mostly originating from the deserts in Mongolia and northern China that often contains industrial pollutants ― occurred less frequently last year from the year before, according to the state-controlled NHIS.

This was one reason why fewer Koreans developed respiratory diseases such as pleural mesothelioma.

In spite of last year’s record, South Korea’s expenditure on health care still rose more quickly than spending in other OECD nations. In 2012, the nation’s health care spending increased 4.9 percent, 3.8 times faster than the OECD average of 1.3 percent.