The board shall cause a full journal of their proceedings to be kept, and shall also cause all their receipts and disbursements of money to be faithfully entered in books to be procured and kept for that purpose, and said journal, and all said books, and all other documents in possession of said board, shall always be open to the inspection of the general assembly of the state of Missouri or any committee appointed by it for that purpose. It shall be the duty of the board to report to the common council or municipal assembly of the said city at each annual session thereof, the number and expenses of the police force employed by it under sections 84.350 to 84.860, and all such other matters as may be of public interest, in connection with the duties assigned it by sections 84.350 to 84.860.