vat-viz.js

 const tooltip = d3
    .select('body')
    .append('div')
    .attr('class', 'tooltip');

  const color = d3
    .scaleLinear()
    .domain([d3.min(vatValues), d3.mean(vatValues), d3.max(vatValues)])
    .range(['green', 'yellow', 'red']);

  const projection = d3
    .geoConicConformal()
    .rotate([-10, 0])
    .center([0, 51])
    .parallels([29.5, 45.5])
    .scale(1255)
    .translate([width / 2, height / 2]);