instruction: Questions Per Day Over Specific Time Period.
response: SELECT COUNT(Id) AS NumPosts, DATEDIFF(dd, MIN(CreationDate), MAX(CreationDate)) AS NumDays, ROUND(CAST(COUNT(Id) AS FLOAT) / CAST(DATEDIFF(dd, (GETDATE() - '##DaysAgo:int?365##'), GETDATE()) AS FLOAT), 2) AS QPD FROM Posts WHERE PostTypeId = 1 AND CreationDate >= GETDATE() - '##DaysAgo##'