South China's metropolis of Shenzhen, a technological powerhouse, saw its gross domestic product (GDP) top 3 trillion yuan (about 471 billion U.S. dollars) in 2021, said the municipal statistics bureau.

Last year, the city's GDP grew 6.7 percent year on year. The output value of new-energy vehicles, industrial robots, smartphones and 3D printing equipment increased 173.9 percent, 60.5 percent, 40.9 percent and 21.2 percent, respectively.

The total profit of the industrial enterprises with annual revenues of more than 20 million yuan in the city reached 340.4 billion yuan in 2021, up 23.7 percent year on year. The industrial investment in Shenzhen grew 27.1 percent from the previous year.

Shenzhen's export volume has ranked first among the cities in the Chinese mainland for 29 consecutive years. The export hit 1.9 trillion yuan in 2021, up 13.5 percent year on year.

The city's total volume of imports and exports stood at 3.5 trillion yuan last year, up 16.2 percent year on year.

As for the fiscal expenditure, the city's spending on health and education increased 15.8 percent and 13.5 percent year on year respectively in 2021, according to the bureau.