The principal amount of the apportionment shall be computed and repaid in the manner prescribed in this article. (

a) On or before the first day of January succeeding the completion of the state project, the Controller shall compute the annual repayment of each apportionment for each grade level maintained by the district, as follows:

(1) He or she shall determine from the certification of the director the total amount of average daily attendance of project children, and the total amount of average daily attendance of indirect project children, in attendance in the grade level maintained by the district for the period commencing with the date of the proclamation of the Governor proclaiming the existence of a state project in the area including the district and ending on June 30th of the fiscal year in which the state project is completed.

(2) He or she shall divide the average daily attendance of the project children by and multiply the quotient by the amount determined by the board pursuant to

Section as the average per pupil cost of construction in the area of the state project.

(3) He or she shall multiply the average daily attendance of the indirect project children by percent. The product shall be divided by and the quotient multiplied by the amount determined by the board pursuant to

Section as the average per pupil cost of construction in the area of the state project.

(4) The total of the amounts computed pursuant to paragraphs (2) and (3) shall be subtracted from the amount of the apportionment to the district. The remainder shall be divided by and the quotient shall constitute the amount of the annual repayment of the apportionment.

(5) Upon application of the district and approval by the board, the total amount of the repayment may be paid in a lump sum or in fewer than years.