| 年份 | 日本 |
|---|---|
| 2023 | - |
| 2022 | 7.64938 |
| 2021 | 7.34085 |
| 2020 | 7.03318 |
| 2019 | 6.89779 |
| 2018 | 6.74417 |
| 2017 | 6.53038 |
| 2016 | 6.46209 |
| 2015 | 6.43755 |
| 2014 | 6.28946 |
| 2013 | 6.19066 |
| 2012 | 6.1165 |
| 2011 | 6.0745 |
| 2010 | 6.10203 |
| 2009 | 6.15654 |
| 2008 | 6.22541 |
| 2007 | 6.3823 |
| 2006 | 6.62601 |
| 2005 | 6.92369 |
| 2004 | 7.39247 |
| 2003 | 7.99457 |
| 2002 | 8.52827 |
| 2001 | 8.69769 |
| 2000 | 8.42554 |
| 1999 | 7.97786 |
| 1998 | 7.51462 |
| 1997 | 7.10944 |
| 1996 | 7.0178 |
| 1995 | 7.2184 |
| 1994 | 7.25256 |
| 1993 | 7.06878 |
| 1992 | 6.88398 |
| 1991 | 6.73627 |
| 1990 | 6.64 |
| 1989 | 6.65186 |
| 1988 | 6.72108 |
| 1987 | 6.73704 |
| 1986 | 6.68509 |
| 1985 | 6.60763 |
| 1984 | 6.53984 |
| 1983 | 6.47249 |
| 1982 | 6.39037 |
| 1981 | 6.29889 |
| 1980 | 6.18677 |
| 1979 | 6.02082 |
| 1978 | 5.77842 |
| 1977 | 5.46893 |
| 1976 | 5.11734 |
| 1975 | 4.79587 |
| 1974 | 4.52893 |
| 1973 | 4.32344 |
| 1972 | 4.21688 |
| 1971 | 4.19449 |
| 1970 | 4.19804 |
| 1969 | 4.24192 |
| 1968 | 4.33896 |
| 1967 | 4.42763 |
| 1966 | 4.47706 |
| 1965 | 4.5017 |
| 1964 | 4.52362 |
| 1963 | 4.53271 |
| 1962 | 4.53535 |
| 1961 | 4.50181 |
| 1960 | 4.43777 |