Number of car per each car type in a month

select month(czl.log_date + interval 8 hour) as month,
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
where month(czl.log_date + interval 8 hour) = '7'
and year(czl.log_date + interval 8 hour) = '2019'
group by 1,2