The stack calculation does not seem to work if any values are set to zero. I have tried with this cell: unemployment.forEach((d, idx) => { if (idx % 170 === 0) { d.unemployed = 0; } })

It's because it defaults to offset: d3.stackOffsetDiverging, which puts zeros on the x axis. You can use `offset: d3.stackOffsetNone` to fix.

This fix it. Thanks