SECTION 1. Paragraph (a) of subdivision (2) of section 5 of chapter 32 of the General Laws, as amended by chapters 21 and 25 of the Acts of 2009, is hereby amended by striking out, in lines 84 to 98 inclusive, the words “ (a) The normal yearly amount of the retirement allowance for any member classified in Group 1, Group 2 or Group 4, who has paid the full amount of regular deductions on the total amount of regular compensation, including deductions specified in subdivision (3A) of section three, and in paragraph (d) of subdivision (1) of section twenty-two, shall, subject to the limitations set forth in this section, be based on the average annual rate of regular compensation received by such member during any period of three consecutive years of creditable service for which such rate of compensation was the highest, or on the average annual rate of regular compensation received by such member during the period or periods, whether consecutive or not, constituting his last three years of creditable service preceding retirement, whichever is the greater, and shall be computed according to the following table based on the age of such member and his number of years and full months of creditable service at the time of his retirement.” and inserting in place thereof the following words:-

(a) For those who entered service prior to January 1, 2012 , the normal yearly amount of the retirement allowance for any member classified in Group 1, Group 2 or Group 4, who has paid the full amount of regular deductions on the total amount of regular compensation, including deductions specified in subdivision (3A) of section three, and in paragraph (d) of subdivision (1) of section twenty-two, shall, subject to the limitations set forth in this section, be based on the average annual rate of regular compensation received by such member during any period of three consecutive years of creditable service for which such rate of compensation was the highest, or on the average annual rate of regular compensation received by such member during the period or periods, whether consecutive or not, constituting his last three years of creditable service preceding retirement, whichever is the greater, and shall be computed according to the following table based on the age of such member and his number of years and full months of creditable service at the time of his retirement. For those who entered service on or after January 1, 2012 the normal yearly amount of the retirement allowance for any member classified in Group 1, Group 2 or Group 4, who has paid the full amount of regular deductions on the total amount of regular compensation, including deductions specified in subdivision (3A) of section three, and in paragraph (d) of subdivision (1) of section twenty-two, shall, subject to the limitations set forth in this section, be based on the average annual rate of regular compensation received by such member during all of said member’s years of employment, with the average rate of regular compensation for each year adjusted for inflation index from that year to the year of retirement of said member, and shall be computed according to the following table based on the age of such member and his number or years and full months of creditable service at the time of his retirement.