Annuity allowance.

Every teacher who shall be retired under the provisions of § 38-2001.03 or § 38-2001.04 shall receive during the remainder of his life a combined annuity composed of: An annuity equal to 1% of his average annual salary received during the 10 years immediately preceding retirement for each year of his whole term of service after June 30, 1926; A sum equal to 1% of his average annual salary received during the 10 years immediately preceding retirement for each year of his whole term of service prior to July 1, 1926, but not to exceed 40 years; and An additional sum of $15 for each year of said service, but in neither case to exceed 40 years, such annuity to be fixed at the nearest multiple of 12 cents and to be payable monthly and to cease and determine at his death.