title: Get overall average and average per 5 minutes on a Time Chart
body: <p>I have a timechart which currently outputs the average value for every 5 minutes over a period of time for the field "SERVICE_TIME_TAKEN" using following query.</p>
  
  <pre><code>service=service1 | timechart span=5m avg(SERVICE_TIME_TAKEN) | fillnull 
  </code></pre>
  
  <p>I want to add a second line on this same time chart which shows the overall average value. This would be a single value which draws a straight line on the chart.</p>
  
  <p>If I make a separate query, I am able to get this single value using following query.</p>
  
  <pre><code>service=service1 | chart avg(SERVICE_TIME_TAKEN)
  </code></pre>
  
  <p>How can I combine these 2 queries to to show the data on a single time chart?</p>
  
  <p>Tried the following but it only shows the line with the 5 min average.</p>
  
  <pre><code>service=service1 | timechart span=5m avg(SERVICE_TIME_TAKEN) as service_time | eventstats avg(SERVICE_TIME_TAKEN) as overall_service_time  | fillnull 
  </code></pre>
  
  <p>This image depicts what I am looking for.
  Orange line is the 5 mins average and blue line is the overall average. </p>
  
  <p><a href="https://i.stack.imgur.com/W1gkh.png" rel="nofollow noreferrer">chart link</a></p>