BEIJING, May 20 (Xinhua) -- China's yuan weakened against a basket of currencies last week, according to the China Foreign Exchange Trade System (CFETS) index.

The CFETS yuan exchange rate composite index, known as the CFETS RMB Index, which measures the yuan's strength relative to a basket of currencies, came in at 93.76 on May 17, the last trading day of last week, a decrease of 1.03 points from a week earlier, according to the CFETS.

The index compares the yuan to the value of 24 currencies, including the U.S. dollar, euro and Japanese yen, which was expanded from a basket of 13 currencies in 2016.

Last week also saw an index that measures the yuan against the Bank for International Settlements currency basket down 1.02 points to 97.4.

The index measuring the yuan against the Special Drawing Rights basket went down 1.01 points to 93.4.