WITH AVERAGE AS ( 
    SELECT
        AVG(POINT) AS AVERAGE 
    FROM
        TEST_RESULTS 
    WHERE
        TEST_ID = '100'
) 
, AVERAGE2 AS ( 
    SELECT
        SQRT( 
            AVG( 
                (T.POINT -  AVERAGE.AVERAGE) * (T.POINT -  AVERAGE.AVERAGE)
            )
        ) AS STANDARD_DEVIATION 
    FROM
        TEST_RESULTS AS T 
        CROSS JOIN AVERAGE 
    WHERE
        TEST_ID = '100'
) 
SELECT 
USER_ID AS USER,
POINT AS PT,
CASE
WHEN STANDARD_DEVIATION  <> 0 THEN ROUND((((POINT - AVERAGE)*10)/STANDARD_DEVIATION ),1) + 50
ELSE
50
END AS DEV_VAL 
FROM
TEST_RESULTS 
CROSS JOIN AVERAGE
CROSS JOIN AVERAGE2 
WHERE
TEST_RESULTS.TEST_ID = '100' 
ORDER BY DEV_VAL  DESC,USER_ID ASC