Q&A for Ubuntu users and developers
select *, count(*) from ( select CAST( cast(DATEPART(YYYY, CreationDate) as varchar) + '-' + cast(DATEPART(MM, CreationDate) as varchar) + '-01' as datetime) [Month], t.TagName from Posts p join PostTags pt on pt.PostId = p.Id join Tags t on t.Id = pt.TagId where TagName in ('dart') ) as X group by TagName, [Month] order by [Month] asc, TagName asc