Stacked Bar for Late vs. On-time projects

Hey Excel gurus,

I'm not very good with making charts in excel yet, but I know exactly what I'm aiming to do with this one so maybe you can help walk me through it. I've attached a dummy workbook that has, essentially, the material I'm working with, but on a much larger scale (with more columns of data that is irrelevant to the chart). I have a workbook here with a number of supervisors who've submitted multiple employee assessments. They either submit them on-time or before the due date (indicated by positive numbers in # of days or 0) or late (indicated by negative numbers in # of days). What I need to do is create a stacked column chart that lists each supervisor on the X axis and then takes the total number of assessments they've completed and creates a stacked column which can show how many of these assessments were late out of the total number of assessments they've completed.

I'm working on figuring it out right now: it's super frustrating when you know exactly what you want to do but lack the know-how.