| 年份 | 美国 |
|---|---|
| 2023 | - |
| 2022 | 121.565 |
| 2021 | 113.569 |
| 2020 | 108.686 |
| 2019 | 107.286 |
| 2018 | 105.395 |
| 2017 | 102.921 |
| 2016 | 101.002 |
| 2015 | 100 |
| 2014 | 99.0094 |
| 2013 | 97.192 |
| 2012 | 95.5195 |
| 2011 | 93.7655 |
| 2010 | 91.857 |
| 2009 | 90.7662 |
| 2008 | 90.1881 |
| 2007 | 88.4909 |
| 2006 | 86.1623 |
| 2005 | 83.5833 |
| 2004 | 81.042 |
| 2003 | 78.9234 |
| 2002 | 77.3959 |
| 2001 | 76.2081 |
| 2000 | 74.529 |
| 1999 | 72.878 |
| 1998 | 71.8652 |
| 1997 | 71.0653 |
| 1996 | 69.8606 |
| 1995 | 68.6045 |
| 1994 | 67.1955 |
| 1993 | 65.7906 |
| 1992 | 64.2672 |
| 1991 | 62.8353 |
| 1990 | 60.7798 |
| 1989 | 58.5868 |
| 1988 | 56.3766 |
| 1987 | 54.4557 |
| 1986 | 53.1416 |
| 1985 | 52.0925 |
| 1984 | 50.4956 |
| 1983 | 48.7373 |
| 1982 | 46.9003 |
| 1981 | 44.1713 |
| 1980 | 40.3531 |
| 1979 | 37.0099 |
| 1978 | 34.1746 |
| 1977 | 31.9288 |
| 1976 | 30.061 |
| 1975 | 28.4929 |
| 1974 | 26.0775 |
| 1973 | 23.9246 |
| 1972 | 22.6816 |
| 1971 | 21.7418 |
| 1970 | 20.6928 |
| 1969 | 19.6075 |
| 1968 | 18.6812 |
| 1967 | 17.8995 |
| 1966 | 17.3527 |
| 1965 | 16.8638 |
| 1964 | 16.5462 |
| 1963 | 16.301 |
| 1962 | 16.1255 |
| 1961 | 15.9273 |
| 1960 | 15.7151 |