§ 1203. Overtime. A member's final average salary shall be calculated in accordance with such provisions of article eight or article eleven of this chapter as govern the member's benefits, except that earnings classified as overtime compensation in an amount in excess of fifteen percent of a member's annual wages not classified as overtime compensation shall be excluded from such calculation. "Overtime compensation" shall mean, for purposes of this section, compensation paid under any law or policy under which employees are paid at a rate greater than their standard rate for additional hours worked beyond those required, including compensation paid under § 134 of the civil service law and § 90 of the general municipal law.