| 年份 | 日本 |
|---|---|
| 2023 | - |
| 2022 | 12.8749 |
| 2021 | 12.5146 |
| 2020 | 12.1758 |
| 2019 | 11.884 |
| 2018 | 11.6018 |
| 2017 | 11.2801 |
| 2016 | 10.9092 |
| 2015 | 10.5228 |
| 2014 | 10.1494 |
| 2013 | 9.79045 |
| 2012 | 9.43684 |
| 2011 | 9.08592 |
| 2010 | 8.73862 |
| 2009 | 8.38492 |
| 2008 | 8.02906 |
| 2007 | 7.67392 |
| 2006 | 7.30735 |
| 2005 | 6.94376 |
| 2004 | 6.59367 |
| 2003 | 6.25939 |
| 2002 | 5.9387 |
| 2001 | 5.63552 |
| 2000 | 5.34095 |
| 1999 | 5.09046 |
| 1998 | 4.88951 |
| 1997 | 4.68256 |
| 1996 | 4.4645 |
| 1995 | 4.25407 |
| 1994 | 4.04915 |
| 1993 | 3.84032 |
| 1992 | 3.63091 |
| 1991 | 3.42124 |
| 1990 | 3.22647 |
| 1989 | 3.03658 |
| 1988 | 2.85596 |
| 1987 | 2.68517 |
| 1986 | 2.53619 |
| 1985 | 2.41383 |
| 1984 | 2.29591 |
| 1983 | 2.17912 |
| 1982 | 2.05341 |
| 1981 | 1.9285 |
| 1980 | 1.81744 |
| 1979 | 1.71841 |
| 1978 | 1.6279 |
| 1977 | 1.54593 |
| 1976 | 1.47606 |
| 1975 | 1.417 |
| 1974 | 1.36812 |
| 1973 | 1.33231 |
| 1972 | 1.2949 |
| 1971 | 1.25581 |
| 1970 | 1.22276 |
| 1969 | 1.18274 |
| 1968 | 1.13991 |
| 1967 | 1.10349 |
| 1966 | 1.07628 |
| 1965 | 1.06217 |
| 1964 | 1.04546 |
| 1963 | 1.01653 |
| 1962 | 0.989621 |
| 1961 | 0.965994 |
| 1960 | 0.940392 |