I have a Grafana dashboard which currently has 6 Stat panels which displays the availability of a particular item as a percentage.

I also have a panel at the top of the dashboard which should display the overall availability as a percentage.

i.e.

Panel 1: 0%
Panel 2: 50%
Panel 3: 100%
Panel 4: 100%
Panel 5: 50%
Panel 6: 100%

The percentage figure to be displayed in the overall should be ((0 + 50 + 100 + 100 + 50 + 100) / 6) * 100 which equals 66%.

How can I achieve this?