Mich. Comp. Laws § 483.112
Every common purchaser and common carrier of natural gas is hereby required to file with the commission on or before April first of each year, upon blanks to be prescribed and furnished by the commission, an annual statement of its income, expenses, operating and corporate accounts for the preceding calendar year, including the state of its finances in capital securities, fixed capital and other related corporate or balance sheet accounts and including also statistical data relating to the production, purchase, transmission and sales of gas by such common purchasers and common carriers of natural gas, its equipment facilities and customers, said statement to be verified by the oath of some officer of the utility knowing the facts stated therein.
MCL 483.112