instruction: Questions per month for a specific tag.
response: SELECT DATEADD(MONTH, DATEDIFF(MONTH, 0, MIN(CreationDate)), 0) AS YearMon, COUNT(*) AS Num FROM Posts INNER JOIN PostTags ON PostTags.PostId = Posts.Id INNER JOIN Tags ON Tags.Id = PostTags.TagId WHERE Posts.PostTypeId = 1 AND Tags.TagName = @TagName GROUP BY YEAR(CreationDate), MONTH(CreationDate) ORDER BY YearMon