New Year's Card - Life expectancy

The D3.js code that I used as the base for the Life Expectancy New Year's card that I designed. You can see the end result of all 4 cards and read about the design process in my blog Saying "Happy new year" with data

You can find the design of the two other cards here

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

body {
  font: 10px sans-serif;
}

.axis path,
.axis line {
  fill: none;
  stroke: #F7F7F7;
  shape-rendering: crispEdges;
}

.axis path {
  display: none;
}

.line {
  fill: none;
  stroke-width: 1px;
  opacity: 0.4;
}

</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script>

var margin = {top: 60, right: 80, bottom: 60, left: 80},
    width = 1000 - margin.left - margin.right,
    height = 460 - margin.top - margin.bottom;

var x = d3.scale.linear()
    .range([0, width])
	.domain([1950,2015]);

var y = d3.scale.linear()
    .range([height, 0])
	.domain([65,85]);

var color = d3.scale.ordinal()
	.range(["#8A9B0F", "#C82026"])
	.domain(["men", "women"]);
	
var colorRange = ['#8a9b0f','#939213','#9b8917','#a3801a','#a9771c','#af6d1e',
	'#b56320','#ba5622','#bf4924','#c43725','#c82026'];
var colorSeq = d3.scale.ordinal()
	.range(colorRange)
	.domain([d3.range(colorRange.length)]);

var xAxis = d3.svg.axis()
    .scale(x)
    .orient("bottom")
	.tickFormat(d3.format("d"));

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left")
	.ticks(5)
	.tickSize(-width, 0, 0);

var line = d3.svg.line()
    .interpolate("cardinal")
    .x(function(d) { return x(d.year); })
    .y(function(d) { return y(d.gender); });

var svg = d3.select("body").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

d3.csv("lifeExpectancy.csv", function(error, data) {
  if (error) throw error;
  
  data.forEach(function (d,i) {
	  d.year = +d.year;
	  d.men = +d.men;
	  d.women = +d.women;
	  d.diff = d.women - d.men;
  })

var rScale = d3.scale.linear()
	.domain([1, Math.round(d3.max(data, function(d) { return d.diff; })) ])
	.range([3, 40]);
	
  var keys = d3.keys(data[0]).filter(function(key) { return key !== "year" && key !== "diff"; });

var genderLines = keys.map(function(name) {
    return {
      name: name,
      values: data.map(function(d) {
        return {
			year: d.year, 
			gender: d[name]};
      })
    };
  });

//Append axes
  svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis);

svg.append("g")
      .attr("class", "y axis")
      .call(yAxis);

//Wrapper for the background circles
	var strokes = svg.append("g").attr("class","strokeWrapper");

//Append difference circles
  	data.forEach(function(d,index) {
	  	var numLoops = Math.round(d.diff);
	  	  
	  	for(var j = 1; j < (numLoops+1); j++) {
		  	strokes.append("circle")
			  	.attr("cx", x(d.year))
			  	.attr("cy", y(Math.random() * (d.men*0.95 - d.women*1.05) + d.women*1.05).toFixed(4))
			  	.attr("r", rScale(j))
			  	.style("stroke", colorSeq(randomIntFromInterval(0,colorRange.length)))
				.style("stroke-width", (Math.random() * (0.5 - 6) + 6).toFixed(1))
				.style("opacity", (Math.random() * (0.05 - 0.1) + 0.1).toFixed(1))
			  	.style("fill", "none");
	  	  }//for j
  	})
  
  	//Append the two lines
  	var lines = svg.selectAll(".lines")
      	.data(genderLines)
    	.enter().append("g")
      	.attr("class", "lines");

lines.append("path")
	      	.attr("class", "line")
	      	.attr("d", function(d) { return line(d.values); })
	      	.style("stroke", function(d) { return color(d.name); });
	  
  	//Append circles
  	var circles = svg.selectAll(".circleWrapper")
		  .data(data)
		  .enter().append("g")
		  .attr("class","circleWrapper")
		  .attr("transform", function(d) { return "translate(" + x(d.year) + ")"; });
	  
  	//Append men
	circles.append("circle")
		  .attr("class", "circleWoman")
		  .attr("cy", function(d) { return y(d.men); })
		  .attr("r", 8)
		  .style("fill", color("men"))
		  .style("fill-opacity", 0.1);

circles.append("circle")
		  .attr("class", "circleMen")
		  .attr("cy", function(d) { return y(d.men); })
		  .attr("r", 3)
		  .style("fill", color("men"))
		  .style("stroke", color("men"))
		  .style("stroke-width", 3)
		  .style("stroke-opacity", 0.3);
	
	//Append women
	circles.append("circle")
		  .attr("class", "circleWoman")
		  .attr("cy", function(d) { return y(d.women); })
		  .attr("r", 8)
		  .style("fill", color("women"))
		  .style("fill-opacity", 0.1);
		    
	circles.append("circle")
		  .attr("class", "circleWoman")
		  .attr("cy", function(d) { return y(d.women); })
		  .attr("r", 3)
		  .style("fill", color("women"))
		  .style("stroke", color("women"))
		  .style("stroke-width", 3)
		  .style("stroke-opacity", 0.3);

});

function randomIntFromInterval(min,max) {
    return Math.floor(Math.random()*(max-min+1)+min);
}

</script>

https://d3js.org/d3.v3.min.js