United States - Gini index
| Date | Gini index |
|---|---|
| 1997 | 40.5 |
| 1996 | 40.3 |
| 1995 | 39.9 |
| 1994 | 40.0 |
| 1993 | 40.4 |
| 1992 | 38.4 |
| 1991 | 38.0 |
| 1990 | 38.3 |
| 1989 | 38.2 |
| 1988 | 37.7 |
| 1987 | 37.2 |
| 1986 | 37.6 |
| 1985 | 37.6 |
| 1984 | 37.3 |
| 1983 | 37.3 |
| 1982 | 36.7 |
| 1981 | 35.5 |
| 1980 | 34.7 |
| 1979 | 34.8 |
| 1978 | 34.8 |
| 1977 | 35.5 |
| 1976 | 35.6 |
| 1975 | 35.7 |
| 1974 | 35.5 |
| 1973 | 36.1 |
| 1972 | 36.7 |
| 1971 | 36.9 |
| 1970 | 36.6 |
| 1969 | 36.0 |
| 1968 | 36.3 |
| 1967 | 36.9 |
| 1966 | 37.8 |
| 1965 | 37.5 |
| 1964 | 38.1 |
| 1963 | 37.6 |