title: Grafana dividing 2 series
body: <p>I'm trying to divide 2 series to get their ratio.
  For example I'm got sites (a.com, b.com, c.com) as * (All sites)
  Each of them has total sections count and errors occurred stats. I'm wanna to show as bars errors/sections where section > errors for each site to each erros for this site. Here I'm whant to got 3 bars.
  <br>So:
  <br>A parser.*.sections.total
  <br>B parser.*.errors.total</p>
  
  <p>X-Axis Mode:Series<br>
  Display:DrawMode: Bars<br></p>
  
  <p>When i'm trying to use divideSeries I'm always got <strong>VallueError</strong>(divideSeries second argument must reference exactly 1 series)</p>