Currently I have VB script which creates Pivot Tables in Excel from an Access database. The PTs are then used to create graphs on the same worksheet as the PT.
The Access database is a list of suppliers and their Performance Review Scores.
My problem is that I now have to create a PT from the Access database which shows the top 5 most improved suppliers by Performance and the 5 who have deteriorated the most between 2 given dates.

I have created PTs which show the average Scores for any particular time period, but I cannot figure out how to create a Pivot Table showing the difference from one period to another. It doesn't help that some suppliers will have multiple reviews in any one period (the current PTs take the average).

Can anyone suggest anything?