(a) The utility whose rates, rules and regulations are being considered shall establish by competent testimony;

1. (1) the annual revenues under the existing rates, rules and regulations that are being considered and under those which said utility proposes to charge;
2. (2) number of units of service rendered (e.g.,kilowatt-hours, M cubic feet, car miles and car hours or telephone calls) for each service classification involved, actual and proposed; and
3. (3) revenue per unit similarly.

(b) Such utility shall establish by competent testimony:

1. (1) the detailed cost of rendering the service to which such rates, rules and regulations are applicable;
2. (2) the cost per unit of service rendered as defined in the preceding paragraph; and
3. (3) other customary operating statistics.

(c) Such revenues and costs shall be:

1. (1) for each of the three years immediately preceding the initiation of the case;
2. (2) for such later periods as the progress of the proceeding will permit; and
3. (3) all changes in said rates, rules and regulations during the entire period shall be fully and exactly set forth.

(d) Such utility shall establish by competent testimony;

1. (1) comparative balance sheets at the end of the four preceding fiscal years and the latest available month;
2. (2) comparative income statements for the three preceding fiscal years and for the current year through the latest available month;
3. (3) amount and bases of charges for depreciation or amortization included in such operating expenses;
4. (4) earned surplus statements for the three preceding fiscal years and for the current year through the latest available month;
5. (5) complete and detailed statements of the merchandising and jobbing business conducted by the utility during the three preceding fiscal years and for the current year through the latest available month, including the revenues applicable thereto, the total expenses incurred in conducting this business, taxes applicable thereto and return on the property used therefor. This testimony shall be complete and in detail and shall include all costs of every kind and description; and
6. (6) the gas purchasing policies and load management practices and how the company is insuring that gas costs for both the test period and rate year are prudent and from the least-cost reliable sources. Such testimony should discuss both the long- and short-term gas procurement plans as well as a description of existing gas supply contracts. This testimony should be complete and in detail, including quantities as well as costs for all sources of gas supply.