If it shall appear to the board from the returns that a majority of the voters voting thereon shall have voted in favor of such question, the board shall, on or before the first day of May and each year thereafter, certify to the county commission as provided in section 247.470 a rate of levy for general purposes of the district, which shall not be in excess of the rate so approved by the voters of the district as herein provided. If it shall appear to the board from the results that a majority of the voters voting thereon shall not have voted in favor of such question, then the board shall certify to the county commission at such time a rate not in excess of that previously approved by a vote of the majority of the voters of the district voting thereon, or not exceeding fifteen cents on one hundred dollars valuation, whichever is higher.