Plot.plot({
y: {grid: true},
color: {scheme: "BuYlRd", domain: [-0.5, 0.5]},
marks: [
Plot.ruleY([0]),
Plot.lineY(
bls,
Plot.map(
{stroke: Plot.window({k: 2, reduce: "difference"})},
{x: "date", y: "unemployment", z: "division", stroke: "unemployment"}
)
)
]
})