The 1983 Amendments changed the age at which delayed retirement credits (DRC) stopped
            accruing from the month before attainment of age 72 to the month before attainment
            of age 70. The percentage that each DRC is worth also changed. In addition, the change
            in full retirement age (FRA) from age 65 to age 67 means that the number of potential
            DRC months also changed.