815 ILCS 636/10.20: Base lease payment.

That portion of the periodic lease payment which shall be the sum of (a) the average periodic lease charge and (b) the average periodic depreciation. For a single payment lease, the base lease payment is the sum of (a) the average periodic lease charge multiplied by the number of months in the term of the lease and (b) the average periodic depreciation multiplied by the number of months in the lease term.