# 20200101: 15245/325.0

# 20210101: 15736/291.0

# 20210110: 15745/285.3

# 20210120: 15756/277.8

# 20210201: 15769/272.7

# 20210210: 15816/274.1

# 20210220: 15872/273.5

# 20210301: 15882/276.1

# 20210310: 15891/278.7

# 20210320: 15938/280.4

# 20210401: 15969/278.1

# 20210410: 15978/276.3

# 20210420: 15983/276.3

# 20210501: 15993/273.3

select count(*), round(avg(age), 1) as avg_age

from (

  select pa.page_id, 

  str_to_date(max(r.rev_timestamp), '%Y%m%d') as ts, 

  datediff(date '20220810', str_to_date(max(r.rev_timestamp), '%Y%m%d')) - 1 as age

  from page pa 

  inner join revision r on r.rev_page = pa.page_id

  where pa.page_namespace = 0 and pa.page_is_redirect = 0 and

  pa.page_title in 

  (

    select pt.page_title

    from page pt

    inner join categorylinks cl on cl.cl_from = pt.page_id

    where pt.page_namespace = 1 and cl.cl_to = "WikiProject_Croatia_articles"

  ) and

  r.rev_timestamp < '20220810'

  group by pa.page_id

) t