instruction: Posts by tag per month.
response: SELECT CAST(YEAR(Posts.CreationDate) AS TEXT(4)), COUNT(0) FROM Tags INNER JOIN PostTags ON PostTags.TagId = Tags.Id INNER JOIN Posts ON Posts.Id = PostTags.PostId WHERE Tags.TagName = 'powerbi' GROUP BY CAST(YEAR(Posts.CreationDate) AS TEXT(4)) ORDER BY 1