The number of people who run small businesses without any employees in the retail sector declined this year, data showed Monday, amid a prolonged slump due to lukewarm private consumption in Asia's fourth-largest economy.

According to the data from the Bank of Korea, the number of small business owners without employees in the sector dropped to 832,000 in May from 851,000 at end 2016.

The end-May tally marks the lowest since October 2015, when the comparable figure was 831,000.

The total number of small business owners in the retail sector, including those with and without employees, was tallied at 1.18 million as of May, down nearly 40,000 from 1.22 million at the end of last year, the data showed.

Experts say snowballing household debt has been a major drag on private consumption, leading many self-employed businessmen in the industry to go out of business.

South Korea's household debt, including credit purchases, hit a record 1,359.7 trillion won ($1.2 trillion) at the end of March.

Sales of key retailers in May grew 6.3 percent to 10.29 trillion won from 9.68 trillion won in 2016, yet, they were mostly driven by online sellers, according to separate data.

Of the total, 13 offline-based retailers, including department stores, discount chains and convenience stores, rose 2.5 percent on-year, while the comparable figure for 13 online shopping malls jumped 15.2 percent. (Yonhap)