China is attempting to complete the world's biggest population census, going door-to-door to document more than one billion people in just 10 days. The once-a-decade headcount aims to gather information on the exact population of major cities and the migration of workers from rural to urban areas. Six million census takers will scour the country, counting every single citizen, including undocumented workers and families who have broken the one-child-per-couple rule. In an attempt to encourage people to be honest, the Government has promised all information will be confidential. There will be no questions on income - so as not to...