Package sales and zone capacity

Hello!

I'm trying to show package sales by zone against the capacity of each zone. I've used the package seat key, but it looks like it's counting unique patrons rather than seats. The small highlighted zone in the image below has 22 seats sold, but 13 unique patrons, so that's not quite right either, I think...

I'm envisioning some sort of stacked column chart with sold seats the lovely green shown, and remaining capacity as another color. But OF COURSE I'm open to better options.

Thanks in advance for your help!