How do I get pivot tables to remain static?
 

When I set up a pivot table specifying certain data, e.g. everything between
4/1/2005 and 4/30/2005, I see that as I add data to the source range that is
outside of the original range, e.g. 5/23/2005, it gets added to the data that
is picked up by the pivot table inquiry. Is there a way to "freeze" the
pivot table query so that it doesn't add additional categories?