Beijing: China's bank card market continued to expand rapidly with transaction volumes soaring 86.9 per cent year on year in 2015, the latest data showed, the media reported. Bank card transactions hit $214 trillion in 2015, according to a report released by the China Banking Association, Xinhua news agency reported on Friday. Chinese banks issued 640 million new cards in 2015, bringing the total to 5.6 billion, or more than four cards per person, the report said. While the industry continued to grow, potential credit risks remained low. Outstanding loans on credit cards overdue for half a year or longer reached $6 billion, up 6.3 percent year on year, compared with a 42 per cent increase a year earlier. Online payment and new technology have provided opportunities of growth for the bank card industry, but banks should improve risk control as new business models emerge, said an official.