title: Count totals by year and month
body: <p>I have a table that looks like this:</p>
  
  <pre><code>id,created,action
  1,'2011-01-01 04:28:21','signup'
  2,'2011-01-05 04:28:21','signup'
  3,'2011-02-02 04:28:21','signup'
  </code></pre>
  
  <p>How do I select and group these so the output is:</p>
  
  <pre><code>year,month,total
  2011,1,2
  2011,2,1
  </code></pre>