Del. Code tit. 3, § 8535

After payment of the dividend on the preferred stock, and after making provision from its net earnings for the reserve fund, as provided in this chapter, the remainder of the net earnings of the association, not required for dividends on the common stock, may, in the discretion of the directors, be distributed as a patronage refund. Patron stockholders may be entitled to patronage refunds at double the rate of patronage refunds to which nonstockholder patrons shall be entitled. Patronage refunds may be credited to the accounts of nonstockholders in the purchase of capital stock of the association.