On or before March 1, 1980, and annually thereafter, the Commissioner of Transportation shall certify to the Governor as eligible to receive the exemption provided by § 12-251, any railroad transporting freight or passengers within this state or between this state and other states which, as of the date of its certification, has been found by the commissioner to have complied with the tax exemption projects issued pursuant to sections 13b-226 to 13b-233, inclusive, for such railroad for the calendar year next preceding, except in minor respects not deemed material by the commissioner in the light of the purposes of said sections, provided no such railroad shall be certified by the commissioner as eligible to receive said exemption unless the value of any expenditure made by such railroad pursuant to § 13b-228 is not less than the amount of tax to be exempted, and provided further if such expenditures are less than the amount of tax to be exempted, the commissioner shall certify such railroad as eligible to receive a partial exemption for any such amounts expended pursuant to said § 13b-228.