DAX Slicer to have no effect when noting is selected

Hi,
This really applies to using a measure in a PBi slicer and filter pane but I have attached excel example

I have a sicer that filters a table to top n items, but if I haven nothing selected in the slicer nothing is visible but in this
case I would like to have the entire tablle

the measures used are a follows;

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The best I have come up with is just to put 100 as the false value in

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This works but is there a 'proper' way to do this, I've attched the PBi fiile as text and an excel pivot show the measures.

Richard.