Finding the median in intersystems cache SQL

Hi,

Is there a way to find the median in Intersystems Cache SQL? I know it is not available as an aggregate function. Also in SQL Server I could try something like: 

SELECT
(
 (SELECT MAX(Score) FROM
   (SELECT TOP 50 PERCENT Score FROM Posts ORDER BY Score) AS BottomHalf)
 +
 (SELECT MIN(Score) FROM
   (SELECT TOP 50 PERCENT Score FROM Posts ORDER BY Score DESC) AS TopHalf)
) / 2 AS Median

However, there is no PERCENT Keyword in Cache as well. Any suggestions?

Thanks