Can you prevent pivot data from disapearing

I have a pivot with various names in the Group. My dilemma is that when I run the pivot today and all the items in the Group are there it works fine but if tomorrow an item is no longer there it disappears from my pivot whereas I need it to show in my pivot with 0 because the following day it may there there again.

Is it possible to ensure nothing drops out of the pivot.

I have ticked the box that says 'for empty cells show ........'

Thanks