Section 35 ILCS 200/10-220 - Valuation(a) For the base year and subsequent tax years, property described in subsection (a) of Section 10-215 shall be classified so that it is valued in relation to 20% of the property's fair cash value. The fair cash value of the property shall be equal to 4 times the annual net income (revenues net of all expenses, including interest, income taxes, and all property maintenance or replacement expenditures whether or not capital in nature, but not including depreciation) actually earned by its owners from the property during the base period.(b) For any tax year prior to the base year, property described in subsections (b) and (c) of Section 10-215 shall be classified and valued so that the fair cash value of the property does not exceed the fair cash value of the property for the 1989 tax year, as adjusted by the percentage increase in valuation of all property in the municipality between 1989 and the tax year.(c) The fair cash value of property described in Section 10-215 shall be determined as specified in this Section and without taking into account (1) the planned or actual construction and improvement of property described in subsection (a) of Section 10-215, or (2) any acquisition, replacement or resale values or alternative uses assumed or imputed in contemplation or in consequence of such planned or actual construction and improvement.(d) Notwithstanding any other provision of this Section, including subsection (c), the aggregate of all property taxes payable on the property described in Section 10-215 shall not be less than: (1) for any tax year prior to the base year, the aggregate property taxes payable on such property for the 1988 tax year;(2) for the base year, $600,000;(3) for the first tax year following the base year, $735,000;(4) for the second tax year following the base year, $870,000;(5) for the third tax year following the base year and for each tax year thereafter, $1,000,000.