BEIJING — China’s commercial crude oil stocks went up 3.24 percent in December compared with a month earlier, while stocks of refined oil products surged 9.1 percent.

The rise was a result of increasing output and falling processing volume.

Gasoline stocks went up during the period as fuel demand falls during the winter season. In December, China’s export of gasoline jumped 18 percent from the previous month.

Demand for diesel also weakened due to a slowdown in construction activities. During the period, exports of diesel fell 1.7 percent.

Data from the National Bureau of Statistics showed China’s output of crude oil stood at 15.98 million tons in December. Through 2017, China’s crude oil output came in at 190 million tons, down 4 percent from a year earlier.