The recipients of the Washington state honors awards shall be selected based on student achievement in both verbal and quantitative areas, as measured by a test or tests of general achievement selected by the superintendent of public instruction, and shall include student performance in the academic core areas of English, mathematics, science, social studies, and languages other than English, which may be American Indian languages. The performance level in such academic core subjects shall be determined by grade point averages, numbers of credits earned, and courses enrolled in during the beginning of the senior year.