SELECT creatordepid, DENSE_RANK() OVER (ORDER BY COUNT(creatordepid) DESC) AS MC,
CASE DENSE_RANK() OVER (ORDER BY COUNT(creatordepid) DESC)
WHEN 1 THEN
100
ELSE
100 - (DENSE_RANK() OVER (ORDER BY COUNT(creatordepid) DESC) - 1) * 5
END FS
FROM destask GROUP BY creatordepid