年份 | 美国 |
---|---|
2023 | - |
2022 | - |
2021 | 1.664 |
2020 | 1.6415 |
2019 | 1.706 |
2018 | 1.7295 |
2017 | 1.7655 |
2016 | 1.8205 |
2015 | 1.8435 |
2014 | 1.8625 |
2013 | 1.8575 |
2012 | 1.8805 |
2011 | 1.8945 |
2010 | 1.931 |
2009 | 2.002 |
2008 | 2.072 |
2007 | 2.12 |
2006 | 2.108 |
2005 | 2.057 |
2004 | 2.0515 |
2003 | 2.0475 |
2002 | 2.0205 |
2001 | 2.0305 |
2000 | 2.056 |
1999 | 2.0075 |
1998 | 1.999 |
1997 | 1.971 |
1996 | 1.976 |
1995 | 1.978 |
1994 | 2.0015 |
1993 | 2.0195 |
1992 | 2.046 |
1991 | 2.0625 |
1990 | 2.081 |
1989 | 2.014 |
1988 | 1.934 |
1987 | 1.872 |
1986 | 1.8375 |
1985 | 1.844 |
1984 | 1.8065 |
1983 | 1.799 |
1982 | 1.8275 |
1981 | 1.812 |
1980 | 1.8395 |
1979 | 1.808 |
1978 | 1.76 |
1977 | 1.79 |
1976 | 1.738 |
1975 | 1.774 |
1974 | 1.835 |
1973 | 1.879 |
1972 | 2.01 |
1971 | 2.266 |
1970 | 2.48 |
1969 | 2.456 |
1968 | 2.464 |
1967 | 2.558 |
1966 | 2.721 |
1965 | 2.913 |
1964 | 3.19 |
1963 | 3.319 |
1962 | 3.461 |
1961 | 3.62 |
1960 | 3.654 |