The directors and divisions of drainage districts under this act N.M. Stat. Ann. § 73-8-1 to 73-8-60 shall be in number, for districts having an area of twenty-five thousand acres or less, 3; for districts having an area of more than twenty-five thousand acres and less than fifty thousand acres, 5; for districts having an area of more than fifty thousand acres and less than seventy-five thousand acres, 7; and for districts having an area of seventy-five thousand acres or more, 9.