[F15.—(1) A departure direction may be given so as to provide that if the circumstances of the case change in such manner as may be specified in the direction a fresh maintenance assessment is to be made.N.I.
(2) Where any such provision is made, the departure direction may provide for the basis on which the amount of child support maintenance is to be fixed by the fresh maintenance assessment to differ from the basis on which the amount of child support maintenance was fixed by any earlier maintenance assessment made as a result of the direction.]