Which should I use on my DB? - Clustered Index or Non Clustered Index or Both
1/ If after upload you do not update the data, only delete the rows older than 30 days.

2/ And if you can sort your file for the upload by Date, Area, Block

=> Then a clustered index on Date,Area,Block will greatly benefit your aggregations on Date, Date + Area, Date+ Area+Block .

It will also help any request with a where condition on Date, Date + Area, Date + Area + Block , whatever the selected columns for the request.