Circumstances under which board not required to find rate base

In arriving at any determination as to the justness or reasonableness of any existing rate, fare or charge or in prescribing a just and reasonable rate, fare or charge, the board shall not be bound: 1. To find a rate base, if it determines that (a) the applicable operating expenses plus depreciation and taxes of conducting the business, for which the rate, fare or charge is established, computed on the basis of the 12 months next preceding the month in which the proceeding is initiated, exceeds the revenue from such operation, during said period, under the existing rates, fares or charges and that the revenue under the proposed increased rates, fares or charges will not exceed such operating expenses, depreciation and taxes, or (b) the gross operating revenue of the public utility, computed on the basis of the 12 months next preceding the month in which the proceeding is initiated, exceeds the depreciated book cost of its property used and useful in its business as a public utility, or (c) the product or service is a new offering and not covered by an existing rate, fare or charge approved by the board. When the board shall prescribe a rate, fare or charge without finding a rate base, it shall, in its determination, make a finding of the facts on the basis of which it prescribed such rate, fare or charge.