SELECT ROUND(AVG(TOTAL_VALUE)) AS SA_MEDIAN
                FROM (
                   SELECT TOTAL_VALUE
                   FROM (
                        SELECT TOTAL_VALUE, ROW_NUMBER() OVER (ORDER BY TOTAL_VALUE) AS ROW, COUNT(*) OVER () AS TOTAL_ROWS
                        FROM CONVENIENCE
                        WHERE 
                            KIND_CODE ='100'
                            AND TOTAL_VALUE > 0
                  ) sub    
              WHERE ROW IN((TOTAL_ROWS + 1) / 2, (TOTAL_ROWS + 3) / 2)
                )