Tenant's Building Share means 2.79% (calculated by dividing the Rentable Area of the Premises (4,430) by the Building Rentable Area (158,952)). Tenant's Building Share of Excess Building Expenses shall normally be computed by multiplying such percentage by Excess Building Expenses, but shall be subject to adjustment as a result of special allocations made pursuant to Section 5.2 and the provisions of Section 5.3. If the Rentable Area of the Premises is changed for any reason, Tenant's Building Share shall be modified by multiplying the percentage specified in this Paragraph by a fraction, the numerator of which shall be the rentable area of the Premises after such change and the denominator of which shall be the rentable area of the Premises immediately before such change. If the rentable area of the Building is changed as a result of any cause not within Landlord's reasonable control (for instance, as a result of a reduction in area due to reconstruction following fire or the exercise or threatened exercise of the right of eminent domain), then Tenant's Building Share shall be recalculated by dividing the rentable area of the Premises after such occurrence by the rentable area of the entire Building after such occurrence.