BEIJING - China's national freight volume, an indicator of economic activity, maintained steady growth in 2017 as the country's economic expansion picked up pace, official data showed Wednesday.

China's railways, highways, waterways and civil airlines carried a total of 47.15 billion tons of cargo last year, up 9.3 percent from the 2016 level, according to data from the National Development and Reform Commission.

In December alone, the country's freight volume was up 2.9 percent year-on-year to 4.16 billion tons.

In breakdown, rail freight grew 10.7 percent to 3.69 billion tons in 2017, while air cargo increased 5.7 percent to 7.06 million tons.

Highway freight volume rose 10.1 percent year-on-year to 36.8 billion tons while waterway freight volume gained 4.3 percent to 6.66 billion tons last year.

China's economy expanded 6.9 percent last year, picking up for the first time in seven years and well above the government annual target of around 6.5 percent.