a. On or before March first in each year, every taxpayer shall return to the commissioner statements or schedules showing the character and value of all its property, as it existed on the first day of January preceding, its capitalization and its indebtedness.
b. On or before April first in each year, every taxpayer shall also return to the commissioner statements or schedules showing its railway operating revenues of the preceding year, all deductions therefrom, and the net railway operating income remaining after such deductions.