(a) When the estimated revenues and expenses related to a proposed facility will significantly affect the operating revenues or operating expenses of an applicant, the applicant shall submit:

1. (1) the system-wide statement for the last year preceding the filing; and

2. (2) a pro forma system-wide and pro forma incremental statement for each of the first three full years of operation of the proposed facility, showing:

   1. (i) annual revenues and volumes of natural gas, subdivided by classes of service and further subdivided by sales to direct industrial customers, sales to other gas utilities and other sales;
   2. (ii) annual operating expenses, classified in accordance with the commission's Uniform System of Accounts; and
   3. (iii) the annual depreciation, depletion, amortization taxes, utility income, and resulting rate of return on net investment and gas plant, including working capital.