In making the assessment, the board shall value the cars by class based on the owner’s acquisition cost, less depreciation. The depreciation shall be computed for these enumerated Association of American Railroad’s, or successor organization’s, car type groups on a straight-line basis with the indicated depreciable life schedules with a maximum of 80 percent depreciation allowed.

1. (a) Stack cars (alpha S): 22 years minus the age at acquisition.
2. (b) Lightweight, low profile intermodal cars (alpha Q): 22 years minus the age at acquisition.
3. (c) Flat cars (alpha F): 22 years minus the age at acquisition.
4. (d) Conventional intermodal cars (alpha P): 22 years minus the age at acquisition.
5. (e) Vehicular flat cars (alpha V): 22 years minus the age at acquisition.
6. (f) All other cars (all other alphas): 25 years minus the age at acquisition.

7. (g) Betterments: the remaining depreciable life of the car to which the betterment is applied.

   Acquisition cost is defined as the expenditures required to be capitalized by generally accepted accounting principles.