The number of exempt years for private institutions eligible for the application of this Act shall be limited as follows:
1. Railroad transport: 5 years.
2. Road construction: 5 years.
3. Mass rapid transit systems: 5 years.
4. Airports: 5 years.
5. Ports and their facilities: 5 years.
6. Parking lots: 4 years.
7. Major facilities for tourism and recreation: 4 years.
8. Bridges and tunnels: 5 years.
The above number of exempt years shall be applied in a continuous manner and shall not be interrupted in any way. During the period of exemption, the private institution shall still calculate and reserve for depreciation according to the service life of fixed assets prescribed by the Income Tax Act.