select b.department, concat(round(sum(if(timestampdiff(second,a.first_clockin,a.last_clockin)/3600 >9.5,1,0)) / count(distinct a.staff_id)*100,1),'%') as ratio from attendent_tb a left join staff_tb b on a.staff_id = b.staff_id group by 1 order by 2 desc;