Historical covered worker data are subject to revision. Covered Workers is defined as those who are paid at some time during the year for employment on which Social Security taxes are due. Beneficiaries as defined as those with monthly benefits in current-payment status as of June 30. Monthly Social Security benefits were first paid starting in January 1940. Data for 1940 computed from Tables 4.B.1 and 5.A.4 from the 1998 Annual Statistical Supplement to the Social Security Bulletin .
Covered workers is defined as in the rest of the table.
Beneficiaries are defined as those with monthly benefits in current-payment status as of December 1940. This is a slightly different basis than that used in the rest of this table. Therefore the ratio for 1940 is only approximately comparable to the data for the subsequent years.