number of elapsed years

the term “number of elapsed years” means (except as otherwise provided by section 104(j)(2) of the Social Security Amendments of 1972) the number of calendar years after 1950 (or, if later, the year in which the individual attained age 21) and before the year in which the individual died, or, if it occurred earlier (but after 1960), the year in which he attained age 62; except that such term excludes any calendar year any part of which is included in a period of disability.