How do I exclude outliers from an aggregate query?

Question

I\'m creating a report comparing total time and volume across units. Here a simplification of the query I\'m using at the moment:

SELECT  m.Unit,
        COUNT(         


        

Answer 1

I think the most robust way is to sort the list into order and then exclude the top and bottom extremes. For a hundred values, you would sort ascending and take the first 95 PERCENT, then sort descending and take the first 90 PERCENT.