I have station built near a city and it was happily transporting passengers, mail, and iron ore. A while back, the iron ore mine shut down and disappeared from the map. I sold off the train hauling the iron ore after making sure I transported the last ton out of the station. Recently, I checked my station rating for transport services and noticed that while I'm doing fine on passengers and mail, there is still a rating for Iron Ore: Very Poor (22%).
Why, if there is no longer any trains servicing that industry type, no quantity of that type of commodity 'waiting' and no longer any industry within the station catchment area, does it still show on my station rating?
I just didn't want a poor rating to affect my overall station rating and my local authority rating with the town.