WITH FIX_RESULTS AS
(SELECT *
FROM TEST_RESULTS
WHERE TEST_ID = '100')
SELECT
USER_ID AS USER,
POINT AS PT,

CASE
WHEN SQRT((SELECT AVG(POWER(POINT - (SELECT AVG(POINT) FROM FIX_RESULTS),2)) FROM FIX_RESULTS))
= 0 THEN 50
ELSE
ROUND(
10*(POINT - (SELECT AVG(POINT) FROM FIX_RESULTS)) /
SQRT((SELECT AVG(POWER(POINT - (SELECT AVG(POINT) FROM FIX_RESULTS),2)) FROM FIX_RESULTS))
+50
,1)
END
AS DEV_VAL
FROM
FIX_RESULTS
ORDER BY DEV_VAL DESC, USER_ID
;