The administrator is hereby authorized to require annual, periodical, or special reports from all motor carriers, subject to the provisions of this chapter; to prescribe the manner and form in which the reports shall be made; and to require from the carriers specific and full, true, and correct answers to all questions upon which the administrator may deem information to be necessary. The annual reports shall give an account of the affairs of the carrier in such form and detail as may be prescribed by the administrator.