年份 | 美国 |
---|---|
2023 | - |
2022 | 6.55585 |
2021 | 6.54805 |
2020 | 6.55069 |
2019 | 6.54997 |
2018 | 6.53036 |
2017 | 6.4841 |
2016 | 6.40894 |
2015 | 6.31679 |
2014 | 6.24506 |
2013 | 6.21368 |
2012 | 6.23211 |
2011 | 6.33842 |
2010 | 6.52394 |
2009 | 6.71119 |
2008 | 6.8611 |
2007 | 6.96723 |
2006 | 7.01907 |
2005 | 7.05947 |
2004 | 7.16799 |
2003 | 7.3499 |
2002 | 7.54992 |
2001 | 7.75741 |
2000 | 7.95566 |
1999 | 8.09918 |
1998 | 8.19998 |
1997 | 8.28086 |
1996 | 8.32549 |
1995 | 8.32762 |
1994 | 8.30399 |
1993 | 8.2533 |
1992 | 8.15106 |
1991 | 8.14343 |
1990 | 8.05235 |
1989 | 7.7344 |
1988 | 7.51161 |
1987 | 7.47628 |
1986 | 7.33085 |
1985 | 7.1 |
1984 | 7.02212 |
1983 | 6.9147 |
1982 | 6.65035 |
1981 | 6.29843 |
1980 | 6.09013 |
1979 | 5.99508 |
1978 | 5.82689 |
1977 | 5.62726 |
1976 | 5.52752 |
1975 | 5.47108 |
1974 | 5.39659 |
1973 | 5.36195 |
1972 | 5.36942 |
1971 | 5.39038 |
1970 | 5.42994 |
1969 | 5.56763 |
1968 | 5.70276 |
1967 | 5.80913 |
1966 | 5.99515 |
1965 | 6.18031 |
1964 | 6.26413 |
1963 | 6.51815 |
1962 | 6.81137 |
1961 | 6.8595 |
1960 | 6.96128 |