BEIJING — China's postal industry has maintained robust expansion since 2016, with revenues soaring and business volumes hiking.

The industry's revenues are expected to surge to 1.1 trillion yuan (about $165.4 billion) at the end of the year, up from 403.9 billion yuan in 2015 and representing an annual growth rate of 22 percent, said Ma Junsheng, head of the State Post Bureau.

The volume of the express delivery sector in China has quadrupled over the past five years to exceed 80 billion packages, ranking first in the world, he said.

The courier sector raked in over 860 billion yuan this year, up from 276.96 billion yuan five years ago, marking an annual growth rate of 25 percent.