Population measures provide insight on the changing size and face of communities, and the distribution of population among ages affects the character of and challenges faced by a community. For example, an area with a large concentration of youth will have different service needs currently and in the future than an area with a large elderly population.

From 2000 to 2016-20 in MetroWest, there was more growth in older age brackets among both male and female. Among males, the greatest increases were in the age brackets of 60-84 (52%) and 85 or older (82%). Females had these reversed, with slightly higher growth in the 60-84 age bracket (36%) than in 85 or older (24%).

Among the under 40 to 59 age bracket, changes were less dramatic and more equal across the genders. The 60 to 84 group grew 36% for females and 52% for males. The growth rates across the age groups demonstrate that females tend to outlive males.

Individuals age into and out of these groups, and this indicator should not be interpreted as a measure of groups moving to or away from the region. The multiyear figures are from the Census Bureau's American Community Survey. The bureau combined 5 years of responses to the survey to provide estimates for smaller geographic areas and increase the precision of its estimates. However, because the information came from a survey, the samples responding to the survey were not always large enough to produce reliable results, especially in small geographic areas. CGR has noted on data tables the estimates with relatively large margins of error. Estimates with three asterisks have the largest margins, plus or minus 50% or more of the estimate. Two asterisks mean plus or minus 35%-50%, and one asterisk means plus or minus 20%-35%. For all estimates, the confidence level is 90%, meaning there is 90% probability the true value (if the whole population were surveyed) would be within the margin of error (or confidence interval). The survey provides data on characteristics of the population that used to be collected only during the decennial census. Data for this indicator are released annually in December.