Our popular name data come from applications for Social Security cards. The graph below shows the number of applicants for a Social Security card by year of birth and sex. The number of such applicants is restricted to U. S. births where the year of birth, sex, State of birth (50 States and District of Columbia) are known, and where the given name is at least 2 characters long.

Although today nearly everyone in the United States has a Social Security card, that was not the case in the early years of the Social Security program. Some people born before 1937 never obtained a Social Security card because their employment was not covered under Social Security or they died before it became covered. Even in more recent years, many of those who died before entering the covered work force never obtained a Social Security card. However, when the Internal Revenue Service began to require a dependent child's Social Security Number on Federal income tax returns (see Tax Reform Act of 1986), such deaths were no longer a significant factor.