title: Calculated Column for proportional map marking
body: <p>Sorry if the title is vague, my mind is completelty blanking on what to do.</p>
  
  <p>I have a data set that holds broadcast stations and counties and a Error-Ticket. I want to visualize this as a proportional size to station numbers and ticket count.</p>
  
  <p>Example if I have 50 Tickets in NYC but the station count is 200 stations and 5 tickets in a county in Montana with only 1 station then Montana's error rate is statistically higher.</p>
  
  <p>I figure it would be a Count([Error-Ticket]) by StationID but of course that isn't it.
  I was also thinking it would be an OVER All type of function but have not gotten the desired results; in fact no results, only syntax errors.</p>
  
  <p>Columns are StationID, String (KTWR, KNOE, WRTV 22.2 ); County, String (Fayette, LEE, Clark); Error-Ticket, String (ABC123, ABC124, ABC125)</p>
  
  <p>Any help would be appreciated.</p>