The directors may apportion the net earnings by paying dividends upon the paid-up capital stock at a rate not exceeding eight percent per annum. They may set aside reasonable reserves out of such net earnings for any association purpose. The directors may, however, distribute all or any portion of the net earnings to members in proportion to the business of each with the association and they may include nonmembers at a rate not exceeding that paid to members. The directors may distribute, on a patronage basis, such net earnings at different rates on different classes, kinds, or varieties of products handled. All dividends declared or other distributions made under this section may, in the discretion of the directors, be in the form of capital stock, capital or equity certificates, book credits, or capital funds of the association. All unclaimed dividends or distributions authorized under this chapter or funds payable on redeemed stock, equity certificates, book credits, or capital funds shall revert to the association at the discretion of the directors at any time after one year from the end of the fiscal year during which such distributions or redemptions have been declared.