Each proprietor, at a proprietary meeting, shall be entitled to vote upon the shares held by him, as follows: upon 2 shares or less, one vote each; upon every 2 shares exceeding 2 and not exceeding 10, one vote; upon every 4 shares exceeding 10 and not exceeding 30, one vote; upon every 6 shares exceeding 30 and not exceeding 60, one vote; and upon every 8 shares exceeding 60, one vote. If 2 or more persons are the joint proprietors of one or more shares they, or any one of them, may vote according to their interest therein in the same manner.