with out_time as(
select attendent_tb.staff_id 
, case when timestampdiff(minute,first_clockin,last_clockin)>570 then 1
else 0 end as out_time 
, department
from attendent_tb
left join staff_tb
on attendent_tb.staff_id = staff_tb.staff_id
)

select department
,concat(round(sum(out_time)/count(*)*100,1),'%') ratio
from out_time
group by 1
order by 2 desc