un-nest

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
    svg { width: 100%; height: 100%; }
  </style>
</head>

<body>
  <script>
    var margin = {top: 20, right: 10, bottom: 20, left: 10};
    var width = 960 - margin.left - margin.right;
    var height = 500 - margin.top - margin.bottom;
    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.tsv("data.tsv", function(data){
      var nested = d3.nest()
        .key(function(d) { return d.year; })
        .entries(data);
    
    	console.log("nested", nested);
      
      var unnested = function(data, children){
				var out = [];
        data.forEach(function(d, i){
          console.log(i, d);
          d_keys = Object.keys(d);
          console.log(i, d_keys)
          values = d[children];
          
          values.forEach(function(v){
          	d_keys.forEach(function(k){
              if (k != children) { v[k] = d[k]}
            })
            out.push(v);
          })
          
        })
        return out;
      }
      
      console.log("unnested", unnested(nested, "values"));
      
    });
    
  </script>
</body>

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js