China's producer price index (PPI), a major measure of inflation at the wholesale level, rose 5.5 percent last year, the National Bureau of Statistics (NBS) announced Thursday.

The December PPI rose 5.9 percent year on year and 0.7 percent from November, the NBS said.

The PPI rose 6.1 percent year on year in November, compared with a 5-percent gain in October.