title: d3.csv doesnt load numeric matrix
body: <p>I want to load an external .csv file using d3.csv.</p>
  
  <p>This is data.csv (created in vim):</p>
  
  <pre><code>x,y
  2,2
  99,18
  </code></pre>
  
  <p>This is the d3 code:</p>
  
  <pre><code>d3.csv("data.csv", function(dataset){
  console.log(d3.max(dataset, function(d){return d["y"];})); 
  });
  </code></pre>
  
  <p>Even though I expected '18' the output in the console I get is '2'. If I change the '18' to another number, e.g. '35' the output is correct again. What am I doing wrong?</p>