WITH DATA_VAR AS(
    WITH DATA_AVE AS(
        SELECT 
            TEST_ID,
            AVG(POINT) AS AVE,
            COUNT(POINT) AS CNT
        FROM
            TEST_RESULTS
        WHERE
            TEST_ID = '100'
        GROUP BY
            TEST_ID
    )
    SELECT
        TEST_RESULTS.TEST_ID,
        AVE,
        SUM((POINT - AVE) * (POINT - AVE) / CNT) AS VAR
    FROM
        TEST_RESULTS
        INNER JOIN
            DATA_AVE ON DATA_AVE.TEST_ID = TEST_RESULTS.TEST_ID
)
SELECT
    USER_ID AS USER,
    POINT AS PT,
    ROUND(
        CASE
            WHEN VAR <= 0.000000001 THEN 50
            ELSE 50 + (POINT - AVE) / SQRT(VAR) * 10
        END
    , 1) AS DEV_VAL
FROM
    TEST_RESULTS
    INNER JOIN
        DATA_VAR ON DATA_VAR.TEST_ID = TEST_RESULTS.TEST_ID
ORDER BY
    DEV_VAL DESC,
    USER_ID ASC