'0 Population Density by Country Persons pe r Persons per sq . mile sq. km Populati on Density of the Ti'e world will becom e mor e crowded in the 21st century. In mid -2000, China alread y had the 1170 and over 450 and over Current Most Populous Count ries highest popu lat ion in the world , with an estimated 780 to 1169 300 to 449 2000 Per sons pe r 2050 (projected) Persons per