with
    t as
    (
        select
            USER_ID,
            POINT
        from
            TEST_RESULTS
        where
            TEST_ID = '100'
    ),
    a as
    (
        select
            avg(POINT) as av
        from
            t
    ),
    t1 as
    (
        select
            USER_ID,
            POINT - av as s,
            POINT
        from
            t, a
    ),
    a1 as
    (
        select
            abs(pow(avg(pow(s, 2)), 0.5)) as av1
        from
            t1
    )
select
    USER_ID as USER,
    POINT as PT,
    case av1
        when 0 then 50
        else round(s * 10 / av1 + 50, 1)
    end
    as DEV_VAL
from
    t1, a1
order by
    DEV_VAL desc,
    USER_ID
;