年份 | 美国 |
---|---|
2023 | - |
2022 | 6.74146 |
2021 | 6.72192 |
2020 | 6.70657 |
2019 | 6.72958 |
2018 | 6.81124 |
2017 | 6.93198 |
2016 | 7.08311 |
2015 | 7.23675 |
2014 | 7.35455 |
2013 | 7.40925 |
2012 | 7.39672 |
2011 | 7.3355 |
2010 | 7.26706 |
2009 | 7.23289 |
2008 | 7.24158 |
2007 | 7.27164 |
2006 | 7.31096 |
2005 | 7.34846 |
2004 | 7.36924 |
2003 | 7.36291 |
2002 | 7.32264 |
2001 | 7.23053 |
2000 | 7.10412 |
1999 | 6.99822 |
1998 | 6.93786 |
1997 | 6.93445 |
1996 | 7.0355 |
1995 | 7.24338 |
1994 | 7.4748 |
1993 | 7.69071 |
1992 | 7.8726 |
1991 | 7.99045 |
1990 | 8.0829 |
1989 | 8.22331 |
1988 | 8.42466 |
1987 | 8.66877 |
1986 | 8.93525 |
1985 | 9.18831 |
1984 | 9.3663 |
1983 | 9.47985 |
1982 | 9.57502 |
1981 | 9.62017 |
1980 | 9.60564 |
1979 | 9.57286 |
1978 | 9.51941 |
1977 | 9.40576 |
1976 | 9.42135 |
1975 | 9.27876 |
1974 | 8.84501 |
1973 | 8.52588 |
1972 | 8.34 |
1971 | 7.99264 |
1970 | 7.61587 |
1969 | 7.42562 |
1968 | 7.26285 |
1967 | 7.10153 |
1966 | 6.84527 |
1965 | 6.67967 |
1964 | 6.62016 |
1963 | 6.42717 |
1962 | 6.17831 |
1961 | 6.13083 |
1960 | 6.12105 |