Middlesex County Population - Massachusetts

Data Item State County
Population, 2019 estimate - (Number)
Year Value
20001,468,934
20011,476,773
20021,473,966
20031,470,427
20041,467,576
20051,465,156
20061,467,985
20071,475,519
20081,487,636
20091,505,006
20101,507,681
20111,524,848
20121,542,867
20131,560,204
20141,574,993
20151,585,432
20161,594,664
20171,603,943
20181,608,470
20191,611,699

Sources: U.S. Census Bureau, Population Estimates Program (PEP), updated annually. Population and Housing Unit Estimates

Definitions:

The Census Bureau's Population Estimates Program (PEP) produces estimates of the population for the United States, its states, counties, cities, and towns, as well as for the Commonwealth of Puerto Rico and its municipios (county-equivalents for Puerto Rico). Additionally, housing unit estimates are produced for the nation, states, and counties. The timing of the release of estimates varies according to the level of geography. See the Schedule of Releases for more information.

Resident Population - All persons who are "usually resident" in a specified geographic area. For the United States, the resident population includes all persons who usually reside in the 50 states and the District of Columbia, but excludes residents of the Commonwealth of Puerto Rico and the Island areas under U.S. sovereignty or jurisdiction (principally American Samoa, Guam, United States Virgin Islands, and the Commonwealth of the Northern Mariana Islands). In addition, the U.S. resident population excludes U.S. Armed Forces overseas and civilian U.S. citizens whose usual place of residence is outside the United States.

Estimates Base - The population count or estimate used as the starting point in the estimates process. It can be the most recent updated Census count or the estimate for a previous date within the same vintage. (The vintage year (e.g., V2019) refers to the final year of the time series). The April 1, 2010 Population Estimates base reflects changes to the 2010 Census population from the Boundary and Annexation Survey (BAS) and other geographic program revisions. It may reflect changes from the Count Question Resolution program. Click on the "Scope and Methodology" link for details for each vintage year.

Population percent change - The difference between the population of an area at the beginning and end of a time period, expressed as a percentage of the beginning population.

Methodology for U.S. and Puerto Rico