Cal. Educ. Code § 41608

For purposes of computation of allowances and apportionments from the State School Fund, whenever computations of apportionments based on average daily attendance are made for high school districts only the attendance in all classes of grades 9 to 12, inclusive, and in all types of ungraded classes that have been reported as attached to, or as a part of, a school that maintains any of grades 9 to 12, inclusive, shall be included.