For purposes of computing the annuity of a child under
section 2031(d) of this title that commences after
October 31, 1969, the dollar amounts specified in
section 2031(d)(3) of this title shall each be increased by the total percentage increases allowed and in force under this section on or after such day and, in the case of a deceased annuitant, the percentages specified in that section shall be increased by the total percent allowed and in force to the annuitant under this section on or after such day.