select job,case when max(t.s)%2=0 then round(max(s)/2,0) else round((max(s)+1)/2,0) end as start, case when max(t.s)%2=0 then round(max(s)/2+1,0) else round((max(s)+1)/2,0) end as start from (select job,row_number()over(partition by job order by score) s from grade) t group by t.job