Number of cars per week Rahil _ doubt to find cumulative inc

set @start := '2018-12-31 00:00';

select
Date(date_sub(czl.log_date , interval 1 day)) as week,
weekday(date_sub(czl.log_date , interval 1 day)) as weekday,
count(distinct czl.car_id ) as ncars
from car_zone_logs czl
where czl.log_date + interval '8' hour >= @start
and czl.car_state = 'normal'
and czl.zone_state = 'normal'
and czl.csa_state = 'normal'
and weekday(date_sub(czl.log_date , interval 1 day)) = 6
group by 1;