China goes door-to-door in world's biggest census

BEIJING — China kicked off its once-a-decade census Monday, a whirlwind 10-day head count that will see 6 million census takers go door-to-door to document the massive demographic changes taking place in the world's most populous country.
The 2000 tally put China's official population at 1.295 billion people. In the 10 years since, there has been an extensive shift in the population base as millions of migrant workers have poured into urban areas from the countryside.
It is the sixth time China has carried out a national census but the first time it will count people where they live and not where their resident certificate, or hukou, is legally registered. The change will better track the demographic changes and will find the true size of China's giant cities, the populations of which have up to now only been estimates.