The affairs of all associations incorporated under this chapter shall be managed by such officers and directors as may be chosen in manner prescribed by the bylaws of the association; but each member shall be entitled to cast at least one ballot in all elections and votes, any member having had for six months an average of more than one hundred and not more than five hundred employees to whom he is bound to pay compensation under this chapter shall be entitled to cast two ballots, and each additional five hundred employees shall entitle such member to an additional ballot, but no member shall be entitled to cast more than eight ballots.