title: How many times does each value appear in a column?
body: <p>I have a column with time data like this:</p>
  
  <pre><code>17:27:31
  17:27:32
  17:27:32
  17:27:33
  17:27:33
  17:27:34
  17:27:34
  17:27:34
  17:27:35
  17:27:36
  </code></pre>
  
  <p>I want to count how many times each value repeats:</p>
  
  <pre><code>Value      Count
  17:27:31   1
  17:27:32   2
  17:27:33   2
  17:27:34   3
  17:27:35   1
  17:27:36   1
  </code></pre>
  
  <p>How can I do such a thing?</p>