The population rose from 7400 in 1900 to 13,900 in 1910, 20,000 in 1920, and 37,000 in 1940. In 2006 the population of [[Pima County, Arizona|Pima County]], in which Tucson is located, passed one million while the City of Tucson's population was 535,000. | The population rose from 7400 in 1900 to 13,900 in 1910, 20,000 in 1920, and 37,000 in 1940. In 2006 the population of [[Pima County, Arizona|Pima County]], in which Tucson is located, passed one million while the City of Tucson's population was 535,000. |