Sales of China's digging machines surged 45 percent year on year in 2018, industrial data showed Monday.

The country's 25 leading excavator makers sold 203,420 digging machines last year, with 184,190 sold domestically and 19,100 sold overseas, up 41.1 percent and 97.5 percent year on year respectively, according to the China Construction Machinery Association.

Sales of digging machines are an indicator of the vitality of an economy as demand is usually backed by growth in mining and infrastructure development.

Official data showed that China's infrastructure investment expanded 3.7 percent year on year in the first 11 months of 2018.