Source: U.S. Bureau of the Census, County Population Estimates by Demographic Characteristics - Age, Sex, Race, and Hispanic Origin; updated annually for states and counties. http://www.census.gov/popest/counties/asrh/. 2000 Census of Population and Housing for places; updated every 10 years. http://factfinder.census.gov
Sex classification is based on self-identification by gender, either male or female.
The number of females is expressed as a percent of the total population.
Scope and Methodology:
The 2000 data on sex were derived from answers to a question that was asked of all people in Census 2000.
Estimates for states and counties for years after 2000 are developed using a cohort-component method whereby each component of population change - births, deaths, domestic migration, and international migration - is estimated separately for each birth cohort by sex, race, and Hispanic origin.