Number of questions posted to the site per month, plotted by month. "# Questions w/Deleted" counts all questions posted, including those that have since been deleted. "# Non-Deleted Questions" counts just those that remain un-deleted. "# Deleted Questions" is a plot of the difference between these two curves. "# Closed Questions" plots a count of the subset of **un-deleted questions** that are closed.
Q&A for those who study, teach, research and apply economics and econometrics
SELECT MIN(pwd.CreationDate), --DATEDIFF(month, CURRENT_TIMESTAMP, MAX(p.CreationDate)) AS 'Months Ago', COUNT((CAST(YEAR(pwd.CreationDate) as nvarchar(4)) + '-' + CAST(MONTH(pwd.CreationDate) as nvarchar(2)))) AS '# Questions w/Deleted', COUNT((CAST(YEAR(p.CreationDate) as nvarchar(4)) + '-' + CAST(MONTH(p.CreationDate) as nvarchar(2)))) AS '# Non-Deleted Questions', COUNT((CAST(YEAR(pwd.CreationDate) as nvarchar(4)) + '-' + CAST(MONTH(pwd.CreationDate) as nvarchar(2)))) - COUNT((CAST(YEAR(p.CreationDate) as nvarchar(4)) + '-' + CAST(MONTH(p.CreationDate) as nvarchar(2)))) AS '# Deleted Questions', COUNT((CAST(YEAR(pc.CreationDate) as nvarchar(4)) + '-' + CAST(MONTH(pc.CreationDate) as nvarchar(2)))) AS '# Closed Questions' FROM PostsWithDeleted pwd LEFT JOIN Posts p ON pwd.Id = p.Id LEFT JOIN Posts pc ON pwd.Id = pc.Id AND pc.ClosedDate IS NOT NULL WHERE pwd.PostTypeId = 1 GROUP BY (CAST(YEAR(pwd.CreationDate) as nvarchar(4)) + '-' + CAST(MONTH(pwd.CreationDate) as nvarchar(2))) ORDER BY MIN(pwd.CreationDate) ASC