with a as(
select
answer_date,
round(count(issue_id)/count(distinct author_id),2) as per_num
from
answer_tb
group by
answer_date
order by
answer_date
)
select * from a

with a as(
select
answer_date,
round(count(issue_id)/count(distinct author_id),2) as per_num
from
answer_tb
group by
answer_date
order by
answer_date
)
select * from a