Gives the age distribution of each agency's fleet, by vehicle type.

Keywords: fleet age, manufacture year,  commuter rail locomotive, coach, bus, van, automobile, cutaway, aerial tramway, articulated bus, automated guideway vehicle, cable car, commuter rail passenger coach, self-propelled commuter rail passenger car, double decker bus, ferryboat, heavy rail passenger car, inclined plane vehicle, light rail vehicle, minivan, monorail vehicle, over the road bus, school bus, sports utility vehicle, streetcar, trolleybus, vintage trolley, average age, vehicle age