| 年份 | 日本 |
|---|---|
| 2023 | - |
| 2022 | 6.01531 |
| 2021 | 6.20582 |
| 2020 | 6.42414 |
| 2019 | 6.67304 |
| 2018 | 6.94379 |
| 2017 | 7.17317 |
| 2016 | 7.31444 |
| 2015 | 7.35482 |
| 2014 | 7.28564 |
| 2013 | 7.13708 |
| 2012 | 7.01036 |
| 2011 | 6.76838 |
| 2010 | 6.52027 |
| 2009 | 6.43018 |
| 2008 | 6.32095 |
| 2007 | 6.14841 |
| 2006 | 6.10834 |
| 2005 | 6.10679 |
| 2004 | 5.98932 |
| 2003 | 5.92391 |
| 2002 | 5.88145 |
| 2001 | 5.86847 |
| 2000 | 5.92138 |
| 1999 | 5.99685 |
| 1998 | 6.08697 |
| 1997 | 6.27008 |
| 1996 | 6.54619 |
| 1995 | 6.87422 |
| 1994 | 7.36566 |
| 1993 | 7.98408 |
| 1992 | 8.52075 |
| 1991 | 8.68365 |
| 1990 | 8.42554 |
| 1989 | 8.02681 |
| 1988 | 7.62455 |
| 1987 | 7.28646 |
| 1986 | 7.25979 |
| 1985 | 7.49718 |
| 1984 | 7.5389 |
| 1983 | 7.36504 |
| 1982 | 7.20138 |
| 1981 | 7.07286 |
| 1980 | 7.00784 |
| 1979 | 7.06473 |
| 1978 | 7.17733 |
| 1977 | 7.23872 |
| 1976 | 7.2402 |
| 1975 | 7.21112 |
| 1974 | 7.18362 |
| 1973 | 7.15275 |
| 1972 | 7.10243 |
| 1971 | 7.05197 |
| 1970 | 7.01158 |
| 1969 | 6.95628 |
| 1968 | 6.87742 |
| 1967 | 6.78595 |
| 1966 | 6.64407 |
| 1965 | 6.49739 |
| 1964 | 6.34221 |
| 1963 | 6.13771 |
| 1962 | 5.95404 |
| 1961 | 5.82948 |
| 1960 | 5.71983 |