Demographics Find the projected population of each location in 2015. a. In Honolulu, Hawaii, the population was 836,231 in 1990. The average yearly rate of growth is 0.7%. b. The population in Kings County, New York has demonstrated an average decrease of 0.45% over several years. The population in 1997 was 2,240,384. c. Janesville, Wisconsin had a population of 139,420 in 1980 and 139,510 in 1990. 139,735 d. The population in Cedar Rapids, Iowa was 169,775 in the 1980 U.S. Census and 168,767 in the 1990 U.S. Census.​