History graphs for vehicles

[Nathkel]

One of the things i'm missing to help me locate distribution problems is the performance chart for individual routes or the vehicles that use them. We have a delivered cargo graph for the company, and histories of waiting cargo for a chosen station, but i could use one for any given route (set of vehicle orders) or vehicle.

If it works well enough, we can see history lines for any cargo it carries, including refits.
By showing the total distribution for a route, it will help me determine if thats what needs to be tweaked rather than more effective vehicles.