How is the world's largest census carried out?

BEIJING, May 11 (Xinhua) -- China released the results of the seventh national census on Tuesday. The census, the largest of its kind across the world, is completed with concerted efforts from all over the country lasting more than a year, statistics officials said Tuesday.

The State Council, or the country's cabinet, established a leading group for China's seventh national census led by Vice Premier Han Zheng, said Li Xiaochao, deputy head of the National Bureau of Statistics (NBS).

A total of 679,000 census-taking institutions were created in the country's provinces, cities, counties, townships and villages, and more than 7 million census takers were organized to document demographic information door to door across the country, Li told a press conference.

The country formulated a census plan and seven detailed regulations for the implementation of the plan, providing guidelines and rules for the census work, he added.

ID numbers were for the first time documented as fundamental information for data comparison and confirmation. Indicators related to the elderly were also added to better demonstrate the status of the aging population.

Electronic data collection was adopted for the first time, allowing real-time reporting. Residents were also allowed to document their information online themselves. Big data and cloud technology, services and applications were used in data processing, which has improved the efficiency and quality of the census, said Li.

Zeng Yuping, NBS chief statistician, said after the door-to-door documentation, nearly 1,000 professional workers were organized to perform spot checks on 32,000 households that were randomly selected in 141 counties across the country's 31 provinces, autonomous regions and municipalities. Social supervisors were hired for the whole spot check process.

According to the results of the check, 0.05 percent of the involved population were missed in the census, lower than the internationally recognized standard of 3 percent, proving that the census is credible and of high quality, said Zeng.

China's population on the mainland reached 1.41178 billion, the NBS said Tuesday, citing data from the seventh national census.