The ACS census “county subdivision” data for 2011, 2016, and 2021 in Maine. The spatial unit used shifted from 2011 to 2016 to be more precise and include multi-polygons of the islands. The plots below show individual snapshots of the population in Maine and the number of interviews from towns in the collection.
The leaflet map includes layers showing the 2016 and 2021 ACS census data for populations of coastal regions and a layer with the number of interviews.