Limitation on Application of Y Values

6.4  To the extent that at any time since the Service Commencement Date:

(a)  the net increase in the aggregate number of Apparatus as a result of Accruals and De-Accruals pursuant to paragraphs 3, 4 and 5 is greater than five per cent (5%) of the total number of Apparatus as at the Service Commencement Date; or

(b)  the net decrease in the aggregate number of Apparatus as a result of Accruals or De-Accruals pursuant to paragraphs 3, 4 and 5 is greater than two per cent (2%) of the total number of Apparatus as at the Service Commencement Date,

then any subsequent Accrual or De-Accrual shall be dealt with as an Authority Change under the Change Protocol.  Provided that the parties may agree not to refer the matter to the Change Protocol but continue to use the Y Values set out in Table 2 of paragraph 4.1 of the Payment Mechanism.