Q&A for project managers
select year(p.creationdate) as 'year', (count(ur.id)/(count(u.id))) as 'count of users' from posts p join users u on p.owneruserid = u.id left join users ur on p.owneruserid = ur.id join posttypes pt on pt.id = p.posttypeid where pt.id = 1 and ur.location like '%Ru%' group by year(p.creationdate) order by year(p.creationdate) desc