Number of cars by City and Car type

select month(czl.log_date + interval 8 hour) as month,
Year(czl.log_date + interval 8 hour) as year,
z.city as city,
cc.car_name as carname,
count(distinct czl.car_id) as ncars
from car_zone_logs czl left join cars c on czl.car_id = c.id
left join car_classes cc on c.car_class_id = cc.id
left join zones z on c.zone_id = z.id
where year(czl.log_date + interval 8 hour) = '2020'
and month(czl.log_date + interval 8 hour) = '4'
and date(czl.log_date + interval 8 hour) = date_sub(CURDATE(), interval 1 day)
and z.city in ('KL','PG','JB','SL')
and czl.zone_state = 'normal'
and c.state = 'normal'
group by 1,2,3,4