All lease payments are payable at the beginning of the lease term and are due 30 days prior to each anniversary date thereafter. Annual rentals of less than $1,000 shall be paid in one lump sum. Annual rentals of $1,000 or more may be paid either in one payment or in two equal payments, at the lessee’s option. In the case of two payments the second payment is due on or before the six-month anniversary date.