with avg as (
    select
        avg(POINT) as avg_point
    from
        TEST_RESULTS
    where
        TEST_ID = '100'
)
select
    USER_ID as USER,
    POINT as PT,
    case
        when sqrt(avg((POINT - avg_point) * (POINT - avg_point)) over ()) = 0 then 50
        else
            round(
                (
                    (
                        (POINT - avg_point) * 10
                    )
                    / sqrt(avg((POINT - avg_point) * (POINT - avg_point)) over ())
                ) + 50
            ,1)
    end as DEV_VAL
from
    TEST_RESULTS,
    avg
where
    TEST_ID = '100'
order by
    3 desc,
    1