world population to reach from 6 to 7-billion mark

It has taken just 12 years for the world population to reach from 6 to 7-billion mark. World population did not reach 1 billion mark until 1804. It took 123 years to reach the 2-billion mark in 1927, 33 years to reach 3 billion in 1960, 14 years to reach 4 billion in 1974, 13 years to reach 5 billion in 1987 and 12 years to reach 6 billion in 1999. World population is projected to nearly stabilise at just above 10 billion after 2200.  China (19%) and India (17%) together make up 36% of the world population.