The board of directors of an association formed pursuant to sections 44-2901 to 44-2918 shall be comprised of not fewer than five nor more than twenty-one persons and a majority of them must be residents of the State of Nebraska. A person convicted of a felony may not be a director and all directors must be of good moral character and known professional, administrative or business ability, such business ability to include a practical knowledge of insurance, finance, or investment. Unless otherwise provided in the articles of incorporation, the board of directors shall make all bylaws. If the number of, or qualifications for, directors shall be amended in the articles or bylaws, such change shall not affect the incumbent directors for the term of office for which they were elected.