N.J. Stat. Ann. § 3B:18-18

In computing the amount of commissions which may be taken annually pursuant to N.J.S. 3B:18-17, the value of any item of corpus at the time when the item is received by the fiduciary, referred to in this section as the "presumptive value" of the item, may be used as the value of the item, or, at the option of the fiduciary, the value of the item at the end of the period for which the commissions are taken may be used.