§ 72. Reserves, net margins, net retained proceeds, distributions, and patronage refunds. The directors shall periodically set aside reasonable sums for reserves. The net margins or net retained proceeds may, in the discretion of the directors, be distributed at least once every twelve months to members or patrons, by uniform distribution and calculated on such bases as the by-laws or marketing contract may prescribe. Distributions may be credited on account of the issuance to members or patrons of capital stock or other securities of the corporation. In the case of cooperatives with capital stock, dividends shall not exceed twelve per centum per annum on any class of stock.