Q&A for professional mathematicians
SELECT SUM(Case When (v.VoteTypeId=2) Then 1 Else 0 End) AS [Upvotes], SUM(Case When (v.VoteTypeId=3) Then 1 Else 0 End) AS [Downvotes], ROUND((CAST(SUM(Case When (v.VoteTypeId=2) Then 1 Else 0 End) AS decimal))*100.0/(CAST(SUM(Case When (v.VoteTypeId IN (2,3)) Then 1 Else 0 End) AS decimal)),2) AS [Upvotes Percentage] FROM Votes v