年份 | 美国 |
---|---|
2023 | - |
2022 | 4.58959 |
2021 | 4.46689 |
2020 | 4.3796 |
2019 | 4.34253 |
2018 | 4.33969 |
2017 | 4.35128 |
2016 | 4.36691 |
2015 | 4.38027 |
2014 | 4.39605 |
2013 | 4.40923 |
2012 | 4.42621 |
2011 | 4.43601 |
2010 | 4.42821 |
2009 | 4.38214 |
2008 | 4.34011 |
2007 | 4.31481 |
2006 | 4.25973 |
2005 | 4.22292 |
2004 | 4.20701 |
2003 | 4.13799 |
2002 | 4.07858 |
2001 | 4.0634 |
2000 | 4.02918 |
1999 | 3.99073 |
1998 | 3.97863 |
1997 | 3.98513 |
1996 | 3.97519 |
1995 | 3.95512 |
1994 | 3.92671 |
1993 | 3.88818 |
1992 | 3.82949 |
1991 | 3.74727 |
1990 | 3.66739 |
1989 | 3.59829 |
1988 | 3.53371 |
1987 | 3.4616 |
1986 | 3.39806 |
1985 | 3.3322 |
1984 | 3.26171 |
1983 | 3.21036 |
1982 | 3.13156 |
1981 | 3.0522 |
1980 | 2.99436 |
1979 | 2.93037 |
1978 | 2.85484 |
1977 | 2.76513 |
1976 | 2.68315 |
1975 | 2.59194 |
1974 | 2.50101 |
1973 | 2.4382 |
1972 | 2.38995 |
1971 | 2.33091 |
1970 | 2.26076 |
1969 | 2.18744 |
1968 | 2.11625 |
1967 | 2.05488 |
1966 | 2.00335 |
1965 | 1.95123 |
1964 | 1.89586 |
1963 | 1.84789 |
1962 | 1.80853 |
1961 | 1.76925 |
1960 | 1.72744 |