The board shall keep minutes of its meetings and a record of all business transacted by it. Its records, except those which the rules of the board require to be held confidential for reasons of public policy, shall be open for inspection by any resident of the city at all reasonable times upon reasonable request. No duplication of records shall be allowed; records shall be examined on city premises and shall not be removed from city premises. The city shall furnish clerical assistance as needed by the board and shall act as the custodian of the records of the board.