年份 | 美国 |
---|---|
2023 | - |
2022 | 6.56825 |
2021 | 6.46867 |
2020 | 6.3512 |
2019 | 6.25654 |
2018 | 6.20221 |
2017 | 6.19689 |
2016 | 6.28134 |
2015 | 6.44913 |
2014 | 6.61804 |
2013 | 6.75229 |
2012 | 6.84737 |
2011 | 6.88165 |
2010 | 6.9003 |
2009 | 6.9805 |
2008 | 7.12832 |
2007 | 7.30313 |
2006 | 7.49523 |
2005 | 7.68456 |
2004 | 7.82031 |
2003 | 7.90807 |
2002 | 7.98152 |
2001 | 8.03115 |
2000 | 8.0406 |
1999 | 8.02739 |
1998 | 7.98834 |
1997 | 7.88902 |
1996 | 7.89613 |
1995 | 7.79959 |
1994 | 7.48305 |
1993 | 7.26745 |
1992 | 7.19163 |
1991 | 7.01847 |
1990 | 6.8101 |
1989 | 6.70292 |
1988 | 6.56541 |
1987 | 6.37434 |
1986 | 6.05579 |
1985 | 5.84827 |
1984 | 5.794 |
1983 | 5.65281 |
1982 | 5.46689 |
1981 | 5.41554 |
1980 | 5.38604 |
1979 | 5.2872 |
1978 | 5.31025 |
1977 | 5.41251 |
1976 | 5.49988 |
1975 | 5.68111 |
1974 | 6.03335 |
1973 | 6.25384 |
1972 | 6.33241 |
1971 | 6.42464 |
1970 | 6.38878 |
1969 | 6.19285 |
1968 | 6.18758 |
1967 | 6.28684 |
1966 | 6.20571 |
1965 | 6.24191 |
1964 | 6.45777 |
1963 | 6.42996 |
1962 | 6.25175 |
1961 | 6.28773 |
1960 | 6.31782 |