Customers select products in a duty-free shopping mall in Haikou, south China's Hainan Province, Oct. 4, 2020. (Xinhua/Pu Xiaoxu)

HAIKOU, Oct. 9 (Xinhua) -- China's resort island province of Hainan raked in 1.04 billion yuan (about 155 million U.S. dollars) in duty-free sales during the National Day holiday, an increase of 148.7 percent year on year, according to customs authorities.

Data from Haikou Customs showed that Hainan's four offshore duty-free shops currently in operation received some 146,800 customers and sold 998,900 duty-free merchandise during the eight-day holiday that ended Thursday, up 43.9 percent and 97.2 percent year on year, respectively.

Hainan's tourism and culture department said more than 4.5 million tourists visited the tropical island during the holiday, with tourism revenue rising 26.6 percent year on year to 6.6 billion yuan.

Starting on July 1, Hainan increased its annual tax-free shopping quota from 30,000 yuan to 100,000 yuan per person.

The range of duty-free goods has also expanded from 38 categories to 45, while the previous tax-free limit of 8,000 yuan for a single product has been lifted.

From July 1 to Sept. 30, Hainan recorded 8.61 billion yuan of duty-free spending by visitors, a surge of 227.5 percent year on year, according to the General Administration of Customs.

China released a master plan in early June on building the southern island province into a globally influential free trade port.