Add Rows to Locked Excel sheet

Hello All - I have a table with a few columns that caters to performance management of a large group of 300+ people. The last 2 columns are formula driven based on inputs on the fields in cells in the table. I would like to lock the column for edits so that the users cannot delete the formula.

While I can achieve that with locking the cells, the challenge is that when the headcount changes (addition or deletion) at a later point in time, addition or deletion of row is not possible if the sheet is protected. The user has to remove protection and add rows.

How can I ensure that with the locked cells, users can add the row to the table.