shall be levied at the rates stated in Schedule One. 7.10 SEV shall have the consent of DCL to undertake Excepted Services without prior notification for which the Additional Charge does not exceed the amount stated in Schedule One and provided it is agreed that the Excepted Services were required; DCL accepts full liability for the payment thereof. Payment for Excepted Services in excess of the value stated in Schedule One that are completed without prior approval of DCL shall be payable in full only at the discretion of DCL 8. Fleet Size 8.1 The prevailing Fleet Size shall be recalculated by SEV and agreed by DCL on the last day of each calendar month for the purpose of calculating Maintenance Charges. 8.2 Spare Vehicles in the ratio of one Spare Vehicle to every ten Operational Vehicles (calculated by Vehicle category, and allowing for reasonable substitutes, across the whole fleet) shall be held at each Site and are included in this Agreement in respect of Fleet Size calculations. 8.3 The Fleet Size shall be allowed to fluctuate within a range defined as the Opening Fleet Size less ten percent to the Opening Fleet Size plus ten percent without penalty or notice. The Fleet Size, in respect of Maintenance Charges calculations shall only be allowed to exceed this range following either a revision of Schedule One agreed by SEV and DCL or on the first day of a DCL Financial Year. 8.4 DCL shall first offer all Surplus Vehicles that DCL wishes to sell for sale to SEV. Any Surplus Vehicle purchased by SEV shall be removed from DCL site within ten working days. Unless purchased by SEV, disposal of Surplus Vehicles shall be the responsibility of DCL. 8.5 Notwithstanding any other term of this Agreement, DCL shall within a period