with
t1 as(
    select
        pay_ability,
        concat(round(count(overdue_days)over(partition by pay_ability)/count(customer_id)over(partition by pay_ability)*100,1),'%') as overdue_ratio
    from
        loan_tb left join customer_tb using(customer_id)
)

select distinct * from t1 order by overdue_ratio desc