select 
city,
round(sum(cnt)/count(distinct driver_id),3) as avg_order_num, 
round(sum(1s)/count(distinct driver_id),3) as avg_income
from(
select driver_id, sum(fare) as 1s, count(order_time) as cnt
from tb_get_car_record as t1
inner join tb_get_car_order as t2
on t1.order_id = t2.order_id
where city = '北京' 
and date(order_time) between '2021-10-01' and '2021-10-07'
group by driver_id
having count(order_time)>=3
) as t