On the first day of January and July of each year, the board shall make and verify a report which shows in detail the kind, character, and amount of improvements constructed in the district, the cost of the improvements, the amount of each warrant paid, the person to whom each warrant was paid, the purpose for which each warrant was paid, and other data necessary to show the condition of improvements made. The report shall be filed with the county clerk in the county or counties in which the district is located and made available for public inspection.