title: Calculate average, max and min based on water year
body: <p>I can calculate the yearly averages, max and min values based on taking the first day of a year as January First like:</p>
  
  <pre><code>    yearly_avg=df2.groupby(years).mean()
      yearly_sum=df2.groupby(years).sum()
      yearly_MAX=df2.groupby(years).max()
      yearly_MIN=df2.groupby(years).min()
  </code></pre>
  
  <p>I need to calculate averages, max and min numbers based on the water year where October 1st is the first day of a year. As an explanation of "water year": <a href="https://en.wikipedia.org/wiki/Water_year" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Water_year</a></p>
  
  <p>Here is my sample file stored here:
  <a href="https://drive.google.com/file/d/1AYi9vp3_DPXHoCPB_YkMQp68FvC_INrV/view?usp=sharing" rel="nofollow noreferrer">https://drive.google.com/file/d/1AYi9vp3_DPXHoCPB_YkMQp68FvC_INrV/view?usp=sharing</a></p>
  
  <p>How can I do that?
  Thanks.</p>