title: How to find the average?
body: <p>I have a dict() like so</p>
  <pre><code>{'5/2020': 51, '11/2021': 16, '10/2021': 13, '1/2020': 15,
   '2/2021': 5, '3/2020': 16, '10/2020': 13, '6/2021': 20, 
   '9/2021': 25, '2/2020': 12, '1/2021': 23, '11/2020': 31, 
   '4/2020': 20, '7/2021': 14, '12/2020': 23}
  </code></pre>
  <p>How do I find the average value per year?</p>