WITH B AS (SELECT POW(AVG(POW(POINT-(SELECT AVG(POINT) AS avg FROM TEST_RESULTS WHERE TEST_ID='100'),2)),0.5) AS b FROM TEST_RESULTS WHERE TEST_ID='100')
    SELECT USER_ID AS USER, POINT AS PT, ROUND(50+(POINT-(SELECT AVG(POINT) AS avg FROM TEST_RESULTS WHERE TEST_ID='100'))*10/(CASE B.b WHEN 0 THEN 1 ELSE B.b END), 1) AS DEV_VAL FROM TEST_RESULTS JOIN B WHERE TEST_ID='100' ORDER BY 3 DESC, 1;