The annual rent due shall be reviewed and adjusted by the manager at the end of the first five-year term and at the end of every five-year term thereafter. Any changes or adjustments shall be based upon changes in the appraised fair market value of the land and improvements being leased, excluding landfill and other improvements placed upon the land by the lessee; provided, however, that the value of landfill and improvements placed by a lessee and not removed on termination or expiration of the lease shall be utilized in the calculation of rentals for subsequent leases of the property with those improvements. [Ord. 98-25 §2, 1998; Ord. 84-61-O §10, 1984; Ord. 78-7-O §2, 1978].