Stacked column diagram with percentage instead of real values data lables

Hello together,

I have created a stacked column diagram of the sales quantity of six different products (please see attached Excle File).

My problem is that I now want to replace the real values data labels in the diagram with the corresponding percentage data labels without changing the current form of my diagram.

Does anybody know how I can do that?

Your help would be very much appreciated.

Thank you in advance!