Chart Pivot Table - How to Select Only 12 Records?

hi Excelers,

This is Excel 2003.

Thru trial-and-error, I have created a simple pivot table chart which pulls data from 1 SQL Server table. The table data contains 2 fields: a number that represents the size of a database and a date (example 1/1/2009)

This table now has 16 rows but I want to only present the most-recent 12 months/rows in the chart.

My trial version looks pretty good, but as more months accumulate, the chart will get too crowded.

My simple question is how can I force the chart to pull only the most-recent/latest 12 records?

Thanks, John