Show average uptimes/throughputs on buildings and transports

Buildings could track their average uptimes over several time windows and report when clicked (e.g. 20% uptime this month, 60% uptime 6 mo, etc); this would help debug production or estimate how much headroom is left. Similarly, transports could display their average throughput over these windows. Perhaps a small graph could show historical changes per building or transport. This data could also translate into some kind of heat map overlay where buildings and transports are colored based on their total utilization.

This would be a very helpful function!
I think it would be sufficient so have a moving average percentage at first, maybe getting a graph later on.