BEIJING, Feb. 12 -- Wednesday's data release by the General Administration of Customs (GAC) broke the mould in its use of the yuan denomination, rather than following the tradition of talking purely in terms of U.S. dollars.

While the figures made headlines in indicating stronger-than-expected foreign trade growth, the release also marked a new policy by the GAC to release two versions of the customs data -- one using Chinese currency the yuan and another using the U.S. dollar denomination.

Spokesman Zheng Yuesheng said that the GAC started to use the yuan to calculate exports, imports and trade surplus figures last February in order to promote international use of the Chinese currency, with the remaining data still denominated in the U.S. dollar.

However, the administration from now on will release two versions of its reports this year, both containing all the customs figures, Zheng said.

He explained that the yuan-dollar conversion is based on an exchange rate released by the country's forex regulator to serve statistical purposes, with monthly changes leading to different results in the two currencies.

The data release showed that China's foreign trade volume climbed 10.3 percent year on year in January to 382.4 billion U.S. dollars, marking a strong start to the year. Meanwhile, in the yuan-denominated version, last month's foreign trade volume was 2.34 trillion yuan, up 7.3 percent from January 2013.

Exports and imports in yuan grew 7.6 percent and 7 percent respectively, both 3 percentage points lower than the dollar-denominated paces.

That disparity represents a remarkable appreciation of the yuan in 2013, while the central parity rate of the Chinese currency against the U.S. dollar appreciated by 3.09 percent, central bank data showed.