Certificates of stock or other written evidence thereof shall be issued for each account in conformity with sections 8-301 to 8-340.01 and the bylaws. Every stockholder shall receive credit on the books of the association for all amounts paid by the stockholder upon the stockholder's subscription for stock, together with the stockholder's pro rata share of all dividends declared, as hereinafter provided, and when the sum of such payments and dividends, less all fines or other charges, equal the par value of the shares of stock held by the stockholder, the stockholder shall be entitled to receive such par value, with such interest not exceeding the legal rate, as the directors may determine, from the time of maturity until paid. Holders of stock thus matured and members desiring to withdraw before such maturity shall be paid the value of their stock in the order of the maturity of or notice of withdrawal of such stock. At no time shall more than two-thirds of the unloaned funds in the treasury of the association, inclusive of such funds applicable to the demands of withdrawing stockholders, as hereinbefore provided, be applicable to the demands of holders of matured stock without the consent of the board of directors.