##                  World population (humans) in millions
##                                     Years
##   Population (millions)
##
## Column1: years A.D.
## Column2: estimated world population in millions
##
## Data points from http://www.census.gov/ipc/www/worldhis.html
## and
## http://www.un.org/esa/population/publications/sixbillion/sixbilpart1.pdf
##
## The population data is taken from the 'lower' estimates column of
## that 1st web page --- column 2 on that page (1AD to 1950).
## Data for years between 1960 and 1999 are from the un.org PDF file.
##
## The Black Plague occurred around 1300-1400, where there is a dip in the estimates.
##
1 170
200 190
600 200
800 220
1000 254
1100 301
1200 360
1250 400
1300 360
1340 443
1400 350
1500 425
1600 545
1650 470
1700 600
1750 629
1800 813
1850 1128
1900 1550
1910 1750
1920 1860
1930 2070
1940 2300
1950 2400
1960 3000
1974 4000
1987 5000
1999 6000