Multiple line chart

Use the z channel (or stroke, or fill) to group tidy data into series and create multiple lines.

Plot.plot({
  y: {
    grid: true,
    label: "↑ Unemployment (%)"
  },
  marks: [Plot.ruleY([0]), Plot.lineY(bls, {x: "date", y: "unemployment", z: "division"})]
})

const bls = FileAttachment("../data/bls-metro-unemployment.csv").csv({typed: true});