8. For the purposes of this Schedule, any reference to the relevant calculation shall be treated as a reference to the calculation of the non-domestic rating contribution which is being made under paragraph 5(2), (3) or (6) of Schedule 8 to the Act, and any reference to a calculation for a preceding year shall be treated as a reference to a calculation of a non-domestic rating contribution made for a preceding year under paragraph 5(6) of Schedule 8 to the Act.