("g")
      .attr("transform", "translate(0," + height + ")")
      .call(d3.axisBottom(x))
      .selectAll("text")
        .style("text-anchor", "end")
        .attr("dx", "-.8em")
        .attr("dy", ".15em")
        .attr("transform", "rotate(-65)");

  // add the y Axis
  var y = d3.scaleLinear()
            .range([height, 0])
            .domain([0, 0.05]);

  // Compute kernel density estimation
  var kde = kernelDensityEstimator(kernelEpanechnikov(7), x.ticks(30))
  var density =  kde( data.map(fun