(b) Any member of any such department who is entitled to a retirement pension under the provisions of subsection (a) of this section and who has been in the honorable service of such department for more than twenty years at the time of his retirement shall receive, in addition to the sixty percent authorized in said subsection (a):
(1) Two additional percent, to be added to the sixty percent for each of the first five additional years of service completed at the time of retirement in excess of twenty years of service up to a maximum of seventy percent; and
(2) One additional percent, to be added to such maximum of seventy percent, for each of the first five additional years of service completed at the time of retirement in excess of twenty-five years of service up to a maximum of seventy-five percent.
The total additional credit provided for in this subsection may not exceed fifteen additional percent.
(c) Any member of any such department whose service has been interrupted by duty with the armed forces of the United States as provided in section twenty-seven of this article prior to the first day of July, one thousand nine hundred eighty-one, shall be eligible for retirement pension benefits immediately upon retirement, regardless of his age, if he shall otherwise be eligible for such retirement pension benefits.
Any member or previously retired member of any such department who has served in active duty with the armed forces of the United States as described in section twenty-seven of this article, whether prior to or subsequent to becoming a member of a paid police or fire department covered by the provisions of this article, shall receive, in addition to the sixty percent authorized in subsection (a) of this section and the additional percent credit authorized in subsection (b) of this section, one additional percent for each year so served in active military duty, up to a maximum of four additional percent. In no event, however, may the total benefit granted to any member exceed seventy-five percent of the member's annual average salary calculated in accordance with subsection (a) of this section.
(d) Any member of a paid police for fire department shall be retired at the age of sixty-five years in the manner provided in this subsection. When a member of the paid police or fire department reaches the age of sixty-five years, the said board of trustees shall notify the mayor of this fact, within thirty days of such member's sixty-fifth birthday. The mayor shall cause such sixty-five-year-old member of the paid police or fire department to retire within a period of not more than thirty additional days. Upon retirement under the provisions of this subsection, such member shall receive retirement pension benefits payable in twelve monthly installments for each year of the remainder of his life in an amount equal to sixty percent of such member's average annual salary or compensation received during the three twelve-consecutive-month periods of employment with such department in which such member received his highest salary or compensation while a member of the department, or an amount of five hundred dollars per month, whichever is greater. If such member has been employed in said department for more than twenty years, the provisions of subsection (b) of this section shall apply.
(e) It shall be the duty of each member of a paid police or fire department at the time a fund is hereafter established to furnish the necessary proof of his date of birth to the said board of trustees, as specified in section twenty-three of this article, within a reasonable length of time, said length of time to be determined by the said board of trustees. Then the board of trustees and the mayor shall proceed to act in the manner provided in subsection (d) of this section and shall cause all members of the paid police or fire department who are over the age of sixty-five years to retire in not less than sixty days from the date the fund is established. Upon retirement under the provisions of this subsection (e), such member, whether he has been employed in said department for twenty years or not, shall receive retirement pension benefits payable in twelve monthly installments for each year of the remainder of his life in an amount equal to sixty percent of such member's average annual salary or compensation received during the three twelve-consecutive-month periods of employment with such department in which such member received his highest salary or compensation while a member of the department, or an amount of five hundred dollars per month, whichever is greater. If such member has been employed in said department for more than twenty years, the provisions of subsection (b) of this section shall apply.