with t1 as ( select l.customer_id, pay_ability, overdue_days from loan_tb l left join customer_tb c on l.customer_id = c.customer_id ) select pay_ability, concat ( round( ( sum( case when overdue_days is not null then 1 else 0 end ) / count(customer_id) ) * 100, 1 ), '%' ) overdue_ratio from t1 group by pay_ability order by overdue_ratio desc