select pay_ability, concat(round(100*count(overdue_days)/count(customer_tb.customer_id),1),'%') as overdue_ratio from loan_tb join customer_tb on loan_tb.customer_id=customer_tb.customer_id group by pay_ability order by overdue_ratio desc
select pay_ability, concat(round(100*count(overdue_days)/count(customer_tb.customer_id),1),'%') as overdue_ratio from loan_tb join customer_tb on loan_tb.customer_id=customer_tb.customer_id group by pay_ability order by overdue_ratio desc