As Additional Rent, Tenant shall pay at the same time the Base Monthly Rent is due an amount equal to Tenant’s Share of that portion of such monthly amortization payment fairly allocable to the Building (as reasonably determined by Landlord) for each month after such improvements are completed until the first to occur of (i) the expiration of the Lease Term (as it may be extended), or (ii) the end of the term over which such costs were amortized.