Staff members work on an assembly line at a farm machinery manufacturing company in Jining City, east China's Shandong Province, Feb. 15, 2022.(Xinhua/Guo Xulei)

BEIJING, May 16 (Xinhua) -- China's value-added industrial output, an important economic indicator, went up 4 percent year on year in the first four months of this year, data from the National Bureau of Statistics showed Monday.