WITH t AS (
    SELECT USER_ID AS USER, POINT AS PT FROM TEST_RESULTS WHERE TEST_ID = '100'
)
, u AS (
    SELECT USER, PT, PT - (SELECT AVG(PT) FROM t) AS PT_GAP FROM t
)
, s AS (
    SELECT SQRT(SUM(POW(PT_GAP, 2)) / (SELECT COUNT(0) FROM u)) AS STD FROM u
)

SELECT
    USER
    , PT
    , IIF(STD = 0, 50, ROUND(PT_GAP * 10 / STD + 50, 1)) AS DEV_VAL
FROM
    u, s
ORDER BY
    DEV_VAL DESC, USER ASC
;