The Public Service Commission shall have general supervision of all persons, firms and corporations operating utilities mentioned in this title, shall inquire into the management of the business and shall keep itself informed as to the manner and method in which the business is conducted. It shall examine such utilities as often as may be necessary to keep informed as to their general condition, their franchises, capitalization, rates and other charges, and the manner in which their plants, equipment and other property are owned, leased, controlled, managed, conducted and operated, not only with respect to adequacy, security and accommodation afforded by their service, but also with respect to their compliance with the provisions of this title, and any other law or laws, with the orders of the commission, and with the charter and franchise requirements. It shall assemble and keep on file, available for the use of the public, full statistics on the foregoing, as well as on all other matters or things connected with such utilities as is necessary to a full knowledge of their business and affairs.