scaleClasses = {
const classCount = 5;
const domain = geoDataJoined.states.features.map((d) => d.properties.per10k);
const thresholds = d3.range(classCount).map((d) => 0.1 + d / classCount / 2);
const range = thresholds.map((d) => d3.interpolateGreys(d));
const scaleClasses = d3.scaleQuantile().domain(domain).range(range);
return scaleClasses;
}