Staff Covid Test Outcomes by Week - How To Pivot Bar Chart

Hi All

This one is really hurting my brain

Management want to see a stacked bar chart that shows the breakdown of tests each week

Each stacked bar should show the number of:
Employees - Positive/Negative/DNA (did not attend)
Contractors - Positive/Negative/DNA
People on site who were not tested

Now I've got my employee & contractor results into the stacked bar chart by week already:

Bar Chart.png

But the last part, adding the people on site that week who were not tested is proving much harding than I could imagine.

The total number of staff on site each week is in a separate table, so I have all the required info, I just can't figure out how to put it together to make the bar chart

I added a column the test results table to pull through the headcount number for that week & site, thinking it might help but I'm still not sure how to get it displayed correctly in the chart

I hope that made sense to someone
Any & all advice welcome
Vicky