The US Census Bureau reported that the 6 billionth person was born at 1.24am on Sunday 18 July 1999. The United Nations however, had set that landmark as 12 October 1999.Every second 5 people are born and 2 people die, a net gain of 3 people. At this rate, the world population will double every 40 years and would be 12 billion in 40 years, 24 billion in 80 years, and more than 48 billion in 120 years. However the United Nations estimate that world population will stabalize at 12 billion in 120 years, citing that effective family planning will result in a universally low birth rate. Education plays a key role: almost half of the 6 billion people are under age 25.