| 年份 | 美国 |
|---|---|
| 2023 | - |
| 2022 | - |
| 2021 | - |
| 2020 | - |
| 2019 | - |
| 2018 | - |
| 2017 | - |
| 2016 | - |
| 2015 | - |
| 2014 | - |
| 2013 | - |
| 2012 | - |
| 2011 | - |
| 2010 | - |
| 2009 | - |
| 2008 | - |
| 2007 | 271.345 |
| 2006 | 270.102 |
| 2005 | 268.893 |
| 2004 | 267.717 |
| 2003 | 266.618 |
| 2002 | 265.5 |
| 2001 | 259.298 |
| 2000 | 256.81 |
| 1999 | 254.275 |
| 1998 | 249.726 |
| 1997 | 246.083 |
| 1996 | 243.41 |
| 1995 | 238.899 |
| 1994 | 238.049 |
| 1993 | 236.28 |
| 1992 | 233.861 |
| 1991 | 235.13 |
| 1990 | 238.41 |
| 1989 | 241.624 |
| 1988 | 244.882 |
| 1987 | 257.831 |
| 1986 | 251.911 |
| 1985 | 248.715 |
| 1984 | 249.035 |
| 1983 | 248.768 |
| 1982 | 248.662 |
| 1981 | 248.841 |
| 1980 | 250.377 |
| 1979 | 258.536 |
| 1978 | 264.311 |
| 1977 | 270.702 |
| 1976 | 272.963 |
| 1975 | 274.572 |
| 1974 | 276.449 |
| 1973 | 276.931 |
| 1972 | 277.533 |
| 1971 | 278.25 |
| 1970 | 279.227 |
| 1969 | 280.326 |
| 1968 | 297.79 |
| 1967 | 312.344 |
| 1966 | 311.317 |
| 1965 | 271.186 |
| 1964 | 268.759 |
| 1963 | 264.793 |
| 1962 | 267.088 |
| 1961 | 259.647 |
| 1960 | - |