title: total value of all radiobuttonlist values
body: <p>I have 20 <code>radiobuttonlists</code> on a page. Each has 4 options with values 1, 2, 3 and 4.</p>
  
  <p>What I need to do is on submitting the form, get the total value of all the <code>radiobuttonlists</code> (eg 3+1+2+3+4...) divided by the total number that have actually been filled in (none of them are required fields so anything from 0 to 20 of them could have been filled in) - hence getting an average value.</p>
  
  <p>Is there an easy / elegant way of doing this?</p>