BEIJING — China's courier sector saw fast expansion in September, with business volume growth estimated at a four-year high, official data showed on Oct 10. 

The China express delivery development index stood at 330.2 last month, up 48.5 percent year-on-year, the State Post Bureau said in a report.

It estimated the sector's business volume at 7.6 billion parcels in September, up 35.7 percent year-on-year, the highest same-period growth in four years.

Compiled on the basis of data from major logistics firms' operating delivery services, the development index reflects the overall business activities and trends in the country's courier sector.

The sub-indices for development scale, service quality and development trend rose 26.8 percent, 87.5 percent and 41.8 percent, respectively, from a year earlier, according to the bureau.

The country's courier sector has been witnessing rapid business growth since February as it recovers from the COVID-19 epidemic. It reported an increase of over 53 percent in business volume during the recent eight-day Golden Week holiday, data from the bureau showed.