The operating income of South Korea’s top 10 conglomerates surged by more than 80 percent on-year in the first quarter of this year, according to Chaebul.com, Wednesday.

The combined operating income of the groups’ 89 nonfinancial subsidiaries increased to 17.9 trillion won ($15.9 billion) with their debt servicing capabilities significantly improved.

The country’s largest automaker Hyundai Motor Group was the only one that suffered a setback, with the operating profit dropping 16.8 percent.

Hyundai Heavy Industries saw the steepest growth of 357.6 percent.

The data also showed that the top 10 groups’ interest payments totaled 899.5 billion won during the same period, down 7.4 percent on-year.