Get the years for which data has been found to be available for an area.
See also
Other data download functions: 
acs_5yr(),
download_selected_files(),
get_area_file_names(),
get_area_groups(),
get_areas(),
get_selected_file_names(),
get_too_heavy_file_names(),
select_area_files(),
unzip_files()
Examples
dir <- system.file("extdata/acs_5yr", package = "geogenr")
ac <- acs_5yr(dir)
years <- ac |>
  get_area_years(area = "State")
