Leases where substantially all the risks and rewards of ownership of assets remain with the lessor are accounted for as operating leases. Annual rentals applicable to such operating leases are charged to expense on a straight-line basis over the lease terms except where an alternative basis is more representative of the pattern of benefits to be derived from the leased assets. Lease incentives received are recognized in the Consolidated Statements of Comprehensive Income as an integral part of the aggregate net lease payments made. Contingent rentals are charged to the Consolidated Statements of Comprehensive Income in the accounting period in which they are incurred.