In each metropolitan utilities district in the State of Nebraska, the board of directors shall cause the accounts of the district to be examined and audited annually. Such examination shall show (1) the gross income from all sources of the district for the previous year, (2) the gross amount of water and gas supplied in the district, (3) the amount expended during the previous year for repairs, (4) the amount expended during the previous year for new machinery, (5) the amount expended in the previous year for property purchased, (6) the amount of depreciation of the plant during the previous year, (7) the cost per thousand gallons of supplying water and per thousand cubic feet for supplying natural gas, (8) the amount collected from the sale and rent of meters, (9) the total assessment made against property for the extension of mains, (10) a detailed statement of all items of expense, (11) the number of employees, (12) the salaries paid employees, (13) the total amount of direct taxes levied by such metropolitan utilities district upon the property within the district, and (14) all other facts necessary to give an accurate and comprehensive view of the cost of maintaining and operating the plant. The audit report shall be filed with the Auditor of Public Accounts within six months after the end of the district’s fiscal year.