Vehicle sales in China rose 13.87 percent in 2013 from a year earlier to 21.98 million units, the China Association of Automobile Manufacturers (CAAM) said on Thursday. In the previous two years, auto sales growth had been below 5 percent. Auto output in 2013 climbed 14.76 percent year on year to 22.12 million units. In December, sales set a monthly record with 2.14 million units sold, up 19.78 year on year and 0.17 percent month on month. Auto exports last year went down 7.46 percent to 977,300 units. Vehicle output and sales are expected to slow down this year. Shi Jianhua, deputy secretary general of CAAM, forecast auto sales to grow 10 percent year on year, while output will climb 8 percent. Many cities have announced restrictions on vehicle sales to cut pollution. The central government has issued several regulations such as restrictions on new vehicle sales. Zhao Fuquan, head of the Research Center for Automotive Industry and Technology Innovation at Tsinghua University, said China's auto sales totaled only about 2 million in 2001, but shot to 22 million in 2013. For China to have so many automobiles is a sharp change, and the country is not well prepared, Zhao said. Smog has been reported frequently in a cluster of cities in recent years and car emissions have been blamed as a culprit in the air pollution. Traffic jams have also strained many cities. Clean-energy cars may be a way out, as well as improved public transportation, Zhao said. China reported 135 million automobiles in October 2013, according to the traffic management bureau of the Ministry of Public Security.