Normalized Stacked Bar Chart

This variation of a stacked bar chart shows percentages rather than absolute numbers.

<!DOCTYPE html>
<meta charset="utf-8">
<style>

.bar {
  fill: steelblue;
}

.axis path {
  display: none;
}

</style>
<svg width="960" height="500"></svg>
<script src="//d3js.org/d3.v4.min.js"></script>
<script>

var svg = d3.select("svg"),
    margin = {top: 20, right: 60, bottom: 30, left: 40},
    width = +svg.attr("width") - margin.left - margin.right,
    height = +svg.attr("height") - margin.top - margin.bottom,
    g = svg.append("g").attr("transform", "translate(" + margin.left + "," + margin.top + ")");

var x = d3.scaleBand()
    .rangeRound([0, width])
    .padding(0.1)
    .align(0.1);

var y = d3.scaleLinear()
    .rangeRound([height, 0]);

var z = d3.scaleOrdinal()
    .range(["#98abc5", "#8a89a6", "#7b6888", "#6b486b", "#a05d56", "#d0743c", "#ff8c00"]);

var stack = d3.stack()
    .offset(d3.stackOffsetExpand);

d3.csv("data.csv", type, function(error, data) {
  if (error) throw error;

data.sort(function(a, b) { return b[data.columns[1]] / b.total - a[data.columns[1]] / a.total; });

x.domain(data.map(function(d) { return d.State; }));
  z.domain(data.columns.slice(1));

var serie = g.selectAll(".serie")
    .data(stack.keys(data.columns.slice(1))(data))
    .enter().append("g")
      .attr("class", "serie")
      .attr("fill", function(d) { return z(d.key); });

serie.selectAll("rect")
    .data(function(d) { return d; })
    .enter().append("rect")
      .attr("x", function(d) { return x(d.data.State); })
      .attr("y", function(d) { return y(d[1]); })
      .attr("height", function(d) { return y(d[0]) - y(d[1]); })
      .attr("width", x.bandwidth());

g.append("g")
      .attr("class", "axis axis--x")
      .attr("transform", "translate(0," + height + ")")
      .call(d3.axisBottom(x));

g.append("g")
      .attr("class", "axis axis--y")
      .call(d3.axisLeft(y).ticks(10, "%"));

var legend = serie.append("g")
      .attr("class", "legend")
      .attr("transform", function(d) { var d = d[d.length - 1]; return "translate(" + (x(d.data.State) + x.bandwidth()) + "," + ((y(d[0]) + y(d[1])) / 2) + ")"; });

legend.append("line")
      .attr("x1", -6)
      .attr("x2", 6)
      .attr("stroke", "#000");

legend.append("text")
      .attr("x", 9)
      .attr("dy", "0.35em")
      .attr("fill", "#000")
      .style("font", "10px sans-serif")
      .text(function(d) { return d.key; });
});

function type(d, i, columns) {
  for (i = 1, t = 0; i < columns.length; ++i) t += d[columns[i]] = +d[columns[i]];
  d.total = t;
  return d;
}

</script>

https://d3js.org/d3.v4.min.js