title: get average of query result
body: <p>Ive got query like this:</p>
  
  <pre><code>select distinct UserID, Count(UserId) as MyNumber from  dbo.User2User group by UserId
  </code></pre>
  
  <p>now I would like extend this query to get MIN, MAX and AVG of MyNumber </p>
  
  <p>no idea how to get to this value from another select or sth ...</p>
  
  <p>thanks for help</p>