The board shall adopt rules necessary for the administration of this subchapter, including a rule providing for:
(1) the manner in which a person may apply for loan repayment assistance; and
(2) a method of awarding assistance under this subchapter that:
(A) gives first priority to applicants who are renewing their applications for loan repayment assistance provided under this subchapter; and
(B) awards any remaining available assistance according to a cumulative ranking system developed by the board based on the number of mathematics and science courses completed by the applicant and the grade received by the applicant for each of those courses.