an amount, on account of the required minimum period of service, equal to fifty percent of his or her final average salary; plus an amount on account of allowable service as a dispatcher member, or fraction thereof, beyond such required minimum period of service equal to two percent of his or her final salary for such allowable service as a dispatcher member during the period from completion of twenty-five years of allowable service as a dispatcher member to the date of retirement but not to exceed more than five years of additional service as a dispatcher member.
N.Y. Retire. and Soc. Sec. Law § 604-E