(1) The board of a school district may admit nonresident pupils to the schools of the district. The board shall determine the rates of tuition of the nonresident pupils and shall collect the tuition.

    (2) Tuition for grades K to 6 shall not exceed 25% more than the operation cost per capita for the number of pupils in membership in grades K to 12.

    (3) Tuition for grades 7 to 12 shall not exceed 12-1/2% more than 115% of the operation cost per capita for the number of pupils in membership in grades K to 12.

    (4) In a school district not maintaining grades above the eighth grade, the tuition shall not exceed 25% more than the operation cost per capita for the number of pupils in membership in grades K to 8.

    (5) The operation costs and membership figures of the preceding fiscal year shall be used. The per capita cost used shall not include moneys expended for school sites, school building construction, equipment, payment of bonds, or other purposes not properly included in operation costs as determined by the state board.