| 年份 | 日本 |
|---|---|
| 2023 | - |
| 2022 | 6.57354 |
| 2021 | 6.48712 |
| 2020 | 6.44405 |
| 2019 | 6.2795 |
| 2018 | 6.16489 |
| 2017 | 6.0764 |
| 2016 | 6.02254 |
| 2015 | 6.03851 |
| 2014 | 6.07943 |
| 2013 | 6.13391 |
| 2012 | 6.27571 |
| 2011 | 6.50323 |
| 2010 | 6.78601 |
| 2009 | 7.23611 |
| 2008 | 7.81335 |
| 2007 | 8.32049 |
| 2006 | 8.4705 |
| 2005 | 8.18958 |
| 2004 | 7.73905 |
| 2003 | 7.27529 |
| 2002 | 6.86943 |
| 2001 | 6.77152 |
| 2000 | 6.96405 |
| 1999 | 6.9972 |
| 1998 | 6.81584 |
| 1997 | 6.6307 |
| 1996 | 6.47726 |
| 1995 | 6.37123 |
| 1994 | 6.36861 |
| 1993 | 6.41945 |
| 1992 | 6.41663 |
| 1991 | 6.34699 |
| 1990 | 6.25117 |
| 1989 | 6.1643 |
| 1988 | 6.08248 |
| 1987 | 5.99386 |
| 1986 | 5.90034 |
| 1985 | 5.78887 |
| 1984 | 5.62725 |
| 1983 | 5.39205 |
| 1982 | 5.0885 |
| 1981 | 4.7389 |
| 1980 | 4.41399 |
| 1979 | 4.14095 |
| 1978 | 3.9282 |
| 1977 | 3.80998 |
| 1976 | 3.7722 |
| 1975 | 3.76173 |
| 1974 | 3.79305 |
| 1973 | 3.8753 |
| 1972 | 3.94939 |
| 1971 | 3.99848 |
| 1970 | 4.02794 |
| 1969 | 4.04707 |
| 1968 | 4.05657 |
| 1967 | 4.06355 |
| 1966 | 4.03105 |
| 1965 | 3.9697 |
| 1964 | 3.91322 |
| 1963 | 3.8691 |
| 1962 | 3.84832 |
| 1961 | 3.86826 |
| 1960 | 3.90886 |