1800 - - - - - - 1,000,000,000
1900 - - - - - - 1,600,000,000
1960 - - - - - - 3,000,000,000
1973 - - - - - - 4,000,000,000
1987 - - - - - - 5,000,000,000
2000 - - - - - - 6,000,000,000
2021 - - - - - - 7,850,000,000
Today - - - http://www.worldometers.info/