title: Divide values in one column by the total number of lines in the file
body: <p>I have several data files in this format:</p>
  <pre><code>orange 25 high
  red 23 low
  blue 20 low
  green 10 high
  </code></pre>
  <p>I would like to divide column 2 by the total number of lines in the file.<br />
  I've tried this:</p>
  <pre><code>awk '{$2=$2/NR}1'
  </code></pre>
  <p>but the output divides the first row by 1, the second by 2 etc.  I want each row divided by the total number of lines in the file.</p>