Counting by government of each decade is called census.
POPULATION OF WORLD -
In 2000 - 6.1 billion.
In children birth per day - 3,36,960
Population of China - 1244 million in 1997.
Population of Switzerland - 8.8 lakh
Population of India - Ist counting in 1872
- in 2001 1.02 billion.
- 17% of world population.
- every 6th person of world is Indian.