chart = Choropleth(unemployment, {
id: d => d.id,
value: d => d.rate,
scale: d3.scaleThreshold,
domain: d3.ticks(2, 10, 5),
range: d3.schemePurples[6],
title: (f, d) => `${f.properties.name}, ${statemap.get(f.id.slice(0, 2)).properties.name}\n${d?.rate}%`,
features: counties,
borders: statemesh,
width: 975,
height: 610
})