| Population Estimates: National Monthly Population | Monthly Population Estimates by Universe, Age, Sex, Race, and Hispanic Origin for the United States // Source: U.S. Census Bureau, Population Division // Universes include the resident population, resident population plus Armed Forces overseas, civilian population, civilian noninstitutionalized population, and household population. The estimates are developed from an April 1, 2020 base population and may incorporate changes resulting from the Count Question Resolution program and/or geographic program revisions. 'In combination' means in combination with one or more other races. The sum of the five race-in-combination groups adds to more than the total population because individuals may report more than one race. Hispanic origin is considered an ethnicity, not a race. Hispanics may be of any race. Responses of 'Some Other Race' from the Census are modified. This results in differences between the population for specific race categories shown in this file versus those in the Census data. // Current data on births, deaths, and migration are used to calculate population change since April 1, 2020. A time series of estimates is produced, beginning with April 1, 2020. The reference date for all estimates is the first of the month. With each new issue of estimates, the entire estimates series is revised. Additional information, including historical and intercensal estimates, evaluation estimates, demographic analysis, research papers, and methodology is available on website: https://www.census.gov/programs-surveys/popest.html | 2021 | pep› natmonthly | Aggregate | geographies | variables | groups | sorts | examples | documentation | http://api.census.gov/data/2021/pep/natmonthly |