It shall be the duty of the trustees or other officers of any hospital or sanitarium receiving any such assistance, to report once a year to the board of supervisors of the county granting such assistance. Such report shall set forth in detail the number of the patients cared for during the year, the average cost per person, the amount of money received from all sources, the amount of money expended and to whom paid, and a tabulated statement of the number of persons admitted, the disease, or other cause of their admission, and the disposition made of each case, which said report shall be included and made a part of the record of said board of supervisors.