The annual fee for administering a trust, as provided in Business and Professions Code, Division 3, Chapter 12, Article 9, Section 7735, may be recovered by withdrawals from current trust income, but total withdrawals in any year shall not exceed four percent (4%) of the trust balance on December 31 of that year, or on the cancellation or maturity date during that year, of all payments deposited into trust, plus all prior years accumulated income. Any remaining current income shall be accumulated in trust.