| 年份 | 美国 |
|---|---|
| 2023 | - |
| 2022 | - |
| 2021 | 1.30856 |
| 2020 | 2.21688 |
| 2019 | 3.35441 |
| 2018 | 1.2279 |
| 2017 | -0.0909228 |
| 2016 | 1.86069 |
| 2015 | 1.58756 |
| 2014 | -0.773398 |
| 2013 | -1.8883 |
| 2012 | -1.45693 |
| 2011 | -3.06946 |
| 2010 | 0.0110513 |
| 2009 | 4.26158 |
| 2008 | 2.45054 |
| 2007 | 1.6018 |
| 2006 | 1.22005 |
| 2005 | 0.837528 |
| 2004 | 1.53886 |
| 2003 | 1.71417 |
| 2002 | 3.83684 |
| 2001 | 3.55821 |
| 2000 | 1.53664 |
| 1999 | 2.76455 |
| 1998 | 1.8726 |
| 1997 | 1.83778 |
| 1996 | 0.449852 |
| 1995 | 0.271204 |
| 1994 | 0.516587 |
| 1993 | -0.0553709 |
| 1992 | 0.650229 |
| 1991 | 1.74454 |
| 1990 | 2.74366 |
| 1989 | 3.07529 |
| 1988 | 1.98512 |
| 1987 | 1.95756 |
| 1986 | 4.58849 |
| 1985 | 4.80876 |
| 1984 | 1.49913 |
| 1983 | 3.02472 |
| 1982 | 2.33015 |
| 1981 | 1.60193 |
| 1980 | 1.49819 |
| 1979 | 0.765306 |
| 1978 | 1.77884 |
| 1977 | 1.77619 |
| 1976 | 0.00131154 |
| 1975 | 2.4406 |
| 1974 | 2.15992 |
| 1973 | -0.856494 |
| 1972 | 0.362383 |
| 1971 | 0.0848252 |
| 1970 | - |
| 1969 | - |
| 1968 | - |
| 1967 | - |
| 1966 | - |
| 1965 | - |
| 1964 | - |
| 1963 | - |
| 1962 | - |
| 1961 | - |
| 1960 | - |