At the moment each month a new row of data is added to the bottom of a
"RawData" sheet, this sheet holds monthly data from 2003.
A Summary sheet details just the last 13 months of data. At the moment, each
month I have to delete the top month and copy and paste the "new" months
data on the bottom.
I believe I can set a formula that will always select the last 13 rows of
data from the "RawData" sheet, I regret I do not know how to go about this,
can anybody help please.

With thanks

Bob