I've never seen that type of expression inside the count function. I wonder if it is valid syntax for FileMaker SQL...
Interestingly enough both COUNT statements work fine as a standalone. It's only when I involve the mathematical operators that it becomes an issue. I thought based on page 27 of https://fmhelp.filemaker.com/docs/13/en/fm13_sql_reference.pdf that this might work, and apparently it works for plain numbers as in SELECT 1/2.
The structure of the query works in mySQL as indicated at http://sqlfiddle.com/#!9/4c181/31 but Filemaker has a more limited set of syntax. I wonder if anyone can think of a workaround or another query structure that might get the job done?
I'm thinking perhaps I could create a virtual list with the two results and then just divide it... then graph that. Just writing this query was a stretch of my ability though. :)
Thanks again for the insight!