10 counties shaded by the rate typically charged in each, with
0 ZIP codes marked as dots. A dot's colour is that
ZIP code's own rate, so a dark dot in a pale county is a town charging more than the
county around it.
County boundaries from Census TIGER/Line 2024. A ZIP code is drawn at the Census
internal point for its ZCTA, which is guaranteed to fall inside it. Codes with no
census geography — PO boxes and single-building codes — are not drawn at all rather
than placed at a guess.