Section 551 - Apportionment1. In order to meet proper health, welfare and safety standards in qualifying schools for the benefit of the pupils enrolled therein, there shall be apportioned health, welfare and safety grants by the commissioner to each qualifying school for the school years beginning on and after July first, nineteen hundred seventy-one, an amount equal to the product of thirty dollars multiplied by the average daily attendance of pupils receiving instruction in such school, to be applied for costs of maintenance and repair. Such apportionment shall be increased by ten dollars multiplied by the average daily attendance of pupils receiving instruction in a school building constructed prior to nineteen hundred forty-seven. In no event shall the per pupil annual allowance computed under this section exceed fifty per centum of the average per pupil cost of equivalent maintenance and repair in the public schools of the state on a state-wide basis, as determined by the commissioner, and in no event shall the apportionment to a qualifying school exceed the amount of expenditures for maintenance and repair of such school as reported pursuant to section five hundred fifty-two of this article.2. The apportionment pursuant to this section shall be reduced by one one hundred eightieth for each day less than one hundred eighty days that such school was actually in total session in the base year, except that the commissioner may disregard such reduction up to five days if he finds that the school was not in session for one hundred eighty days because of extraordinary adverse weather conditions, impairment of heating facilities, insufficiency of water supply, shortage of fuel or the destruction of a school building, and if the commissioner further finds that such school cannot make up such days of instruction during the school year. No such reduction shall be made, however, for any day on which such school was in session for the purpose of administering the regents examinations or the regents scholarship examinations, or any day, not to exceed three days, when such school was not in session because of a conference of teachers called by the principal of the school.