The Boom Heard `Round The World

Later this year, when the United Nations Population Fund marks the birth that puts world population at 6 billion, the number of people on Earth will have increased by nearly 300 percent in the 20th century.

The globe's population has increased by well over 4 billion in the past 100 years, including 2 billion since 1974, according to a report from the Washington- based Population Reference Bureau.

The report, which attributes the dramatic gains to increasing longevity as well as higher overall birth rates, notes that 98 percent of all population growth is taking place in the developing world.

World Population by the Billions

People When reached? How long did it take?

1 billion About 1800 All of human history

2 billion 1930 130 years

3 billion 1960 30 years

4 billion 1974 14 years

5 billion 1987 13 years

6 billion 1999 12 years

Birth Rate by Country

The average number of children a woman would bear in her lifetime.

10 highest 10 lowest

Niger 7.5 Bulgaria 1.09

Oman 7.1 Latvia 1.11

Ethiopia 7.0 Spain 1.16

Gaza 7.0 Czech Republic 1.17

Uganda 6.9 Italy 1.19

Angola 6.8 Slovenia 1.22

Somalia 6.8 Estonia 1.24

Burkina Faso 6.7 Russia 1.24

Mali 6.7 Belarus 1.27

Yemen 6.7 Ukraine 1.28

United States 2.03

SOURCE: Population Reference Bureau