9-Box Grid - Plotting Multiple Employees

I am trying to create a 9-box grid that will plot multiple employees but am having difficulties as I am not an Excel whiz. We generally want to use this for leaders to plot their managers, using a rating scale of 1-3 for both the performance and potential ratings. Ideally, the leader will rate each employees potential (1-3 scale), and performance (1-3 scale), then the employee will be plotted onto the 9-box, in a box not on the axis lines. Attached is a sample of what I am trying to create. Please help!!