with pay_ability_overdue as(
select pay_ability,overdue_days
from loan_tb a left join customer_tb b on a.customer_id=b.customer_id)

select pay_ability,
       concat(round(count(overdue_days)/count(pay_ability)*100,1),'%') as overdue_ratio
from pay_ability_overdue
group by pay_ability
order by overdue_ratio desc