enter data allowed but make impossible to delete data

I'm trying to figure out how to make a table allow values to be entered, but prevent (accidental) deletion.
Example: In the context of a company-wide inventory, teams of two are to count the stocks and enter their values. It should be prevented that values of already entered counts are deleted unintentionally.
A sheet protection prevents the complete editing of a cell.

I am more than grateful if someone has an idea!