40.. | Railroad Transportation |
41.. | Local And Interurban Passenger Transit |
42.. | Trucking And Warehousing |
43.. | U.S. Postal Service |
44.. | Water Transportation |
45.. | Transportation By Air |
46.. | Pipelines, Except Natural Gas |
47.. | Transportation Services |
48.. | Communication |
49.. | Electric, Gas, And Sanitary Services |