The following allowances due under the provisions of sections 87.120 to 87.371 of any member who retired from service shall be increased annually, as approved by the board of trustees beginning with the first increase in the October following his or her retirement and subsequent increases in each October thereafter, at the rates designated:

(1) With a retirement service allowance or ordinary disability allowance:

(a) One and one-half percent per year, compounded each year, up to age sixty for those retiring with twenty to twenty-four years of service,

(b) Two and one-fourth percent per year, compounded each year, up to age sixty for those retiring with twenty-five to twenty-nine years of service,

(c) Three percent per year, compounded each year, up to age sixty for those retiring with thirty or more years of service,

(d) After age sixty, five percent per year for five years;

(2) With an accidental disability allowance, three percent per year, compounded each year, up to age sixty, then five percent per year for five years. Provided, however, for accidental disability on or after August 28, 2011, for reasons other than provided in subsection 3 of section 87.205, unless a member has more than twenty-five years of creditable service, the accidental disability allowance shall only increase at a rate of one percent per year, compounded each year, up to age sixty, then five percent per year for five years. For accidental disability on or after August 28, 2011, for reasons other than provided in subsection 3 of section 87.205, if a member has more than twenty-five years of creditable service, the accidental disability allowance shall only increase at a rate of two and one-fourth percent per year, compounded each year, up to age sixty, then five percent per year for five years.