Population measures provide insight on the changing size and face of communities, and an area's needs and assets. For example, areas with large or growing populations of seniors or children may face challenges in providing needed services and generating enough tax revenue to support those services.

The population of the 9-county Rochester region continues to grow older. The number of people between the ages of 60 and 84 increased 55% between 2000 and 2017-21. The population 85 and older grew 35% during the same period. There were declines in all other age groups, with the largest in people under 20, which shrank 16%. People 40 to 59 overtook those under 20 as the largest age group in the region (312,000 residents compared to 288,000).

New York State and the nation are aging, too, but differently than the Rochester area. Between 2000 and 2017-21, there were smaller increases for the 60-84 age group statewide (45%) and in the U.S. (47%), yet increases were larger for people 85 and older (45% and 51%, respectively). Unlike the Rochester area, there were small gains in the 40 to 59 age group at the state (4%) and national (14%) levels. While New York's 20 to 39 population fell 1% and those under 20 by 9%, the nation had gains of 9% and 4%, respectively.

The counties surrounding Monroe had somewhat larger declines in younger populations, with 20% fewer residents under 20 and 11% fewer residents aged 20-39 in 2017-21 compared to 2000. The population of older residents grew the most in Ontario County (84% for people aged 60-84 and 54% for those 85 and older), while populations of young people decreased the most in Orleans (32% fewer residents under 20).

The multi-year figures are from the Census Bureau's American Community Survey. The bureau combined multiple years of responses to the survey to provide estimates for smaller geographic areas and increase the precision of its estimates. The survey provides data on characteristics of the population that used to be collected only during the decennial census. Data for this indicator are expected to be released in the fourth quarter.