年份 | 美国 |
---|---|
2023 | - |
2022 | 1.82334 |
2021 | 2.02543 |
2020 | 2.28799 |
2019 | 2.60793 |
2018 | 3.05067 |
2017 | 2.46594 |
2016 | 2.85987 |
2015 | 2.9846 |
2014 | 2.99007 |
2013 | 2.84432 |
2012 | 2.99888 |
2011 | 2.95682 |
2010 | 2.76091 |
2009 | 3.01002 |
2008 | 2.47368 |
2007 | 2.43689 |
2006 | 2.81818 |
2005 | 3.16778 |
2004 | 3.49701 |
2003 | 3.57555 |
2002 | 3.5195 |
2001 | 3.13067 |
2000 | 3.18263 |
1999 | 3.61737 |
1998 | 3.14016 |
1997 | 3.36614 |
1996 | 3.4934 |
1995 | 3.96716 |
1994 | 4.10613 |
1993 | 3.84016 |
1992 | 3.89827 |
1991 | 3.60955 |
1990 | 3.21285 |
1989 | 3.20864 |
1988 | 3.63818 |
1987 | 3.51828 |
1986 | 3.94742 |
1985 | 4.50692 |
1984 | 5.15787 |
1983 | 5.3848 |
1982 | 5.479 |
1981 | 6.35834 |
1980 | 4.41123 |
1979 | 3.79436 |
1978 | 4.35701 |
1977 | 4.67803 |
1976 | 5.41053 |
1975 | 5.62699 |
1974 | 5.9902 |
1973 | 6.57949 |
1972 | 7.14386 |
1971 | - |
1970 | - |
1969 | - |
1968 | - |
1967 | - |
1966 | - |
1965 | - |
1964 | - |
1963 | - |
1962 | - |
1961 | - |
1960 | - |