BEIJING, Jan. 23 (Xinhua) -- The central parity rate of the Chinese yuan against the U.S. dollar Tuesday strengthened for the third consecutive trading day to reach its highest level in more than 25 months.

According to data from the China Foreign Exchange Trade System, the central parity rate was 6.4009 yuan per dollar, advancing by 103 pips from Monday and the strongest level since Dec. 7, 2015.

The strong yuan in the past few days was partly due to weakness in the dollar, as the dollar index hovered near a three-year low in the past week.

Since the beginning of this year, the yuan has strengthened by more than 2 percent against dollar.

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.

In China's spot foreign exchange market, the yuan is allowed to rise or fall by 2 percent from the central parity rate each trading day.

The central parity rate of the yuan against the U.S. dollar is based on a weighted average of prices offered by market makers before the opening of the interbank market each business day.