with base as (
    select
        USER_ID as USER
        ,POINT as PT
        ,AVG(POINT) OVER() as AVG_PT
    from
        TEST_RESULTS
    where
        TEST_ID = 100
),
std as (
    select
        pow(cast(sum(pow(PT-AVG_PT,2)) as real)/count(),0.5) as std_
    from
        base
)
select
    USER
    ,PT
    ,case when std_=0 then 50 else round(cast((PT-AVG_PT)*10 as real)/std_+50,1) end as DEV_VAL
from
    base
    cross join
    std
order by
    DEV_VAL desc
    ,USER