Census takers register a resident's information via an electronic device at a community of Suqian city, East China's Jiangsu province, Nov 1, 2020. (Photo: Xinhua)

BEIJING - Census spot-checks are underway in China for quality control after over 7 million staff members completed home visits for headcounts on Dec 10 in the seventh national population census, which began on Nov 1.

After the spot-checks, the census will carry out data processing, evaluation and summarization. The census key data will be published from April 2021, said the State Council leading group on the seventh national population census.

Thirty-one task forces with more than 1,000 staff members will carry out checks on about 32,000 households.

These spot-checks are an independent survey conducted after census registration, an effective way widely used globally to test census data quality.

China has conducted a national population census every ten years since the 1990s. The previous census found its population had increased to 1.37 billion.