WITH
    AVE AS (
        SELECT
            AVG(POINT) AS AVERAGE
        FROM
            TEST_RESULTS
        WHERE
            TEST_ID = '100'
    ),
    SD AS (
        SELECT
            SQRT(
                AVG((POINT - AVE.AVERAGE) * (POINT - AVE.AVERAGE))
            ) AS STANDARD_DEVIATION
        FROM
            TEST_RESULTS
            CROSS JOIN AVE
        WHERE
            TEST_ID = '100'
    )
SELECT
    USER_ID AS USER,
    POINT AS PT,
    CASE
        WHEN SD.STANDARD_DEVIATION <> 0 THEN ROUND(
            (((POINT - AVERAGE) * 10) / STANDARD_DEVIATION),
            1
        ) + 50
        ELSE 50
    END AS DEV_VAL
FROM
    TEST_RESULTS
    CROSS JOIN AVE
    CROSS JOIN SD
WHERE
    TEST_ID = '100'
ORDER BY
    PT DESC,
    USER ASC;