| 年份 | 乍得 |
|---|---|
| 2023 | - |
| 2022 | 8.79072 |
| 2021 | 8.7971 |
| 2020 | 8.77135 |
| 2019 | 8.72558 |
| 2018 | 8.68993 |
| 2017 | 8.66661 |
| 2016 | 8.61726 |
| 2015 | 8.60705 |
| 2014 | 8.64774 |
| 2013 | 8.60497 |
| 2012 | 8.51487 |
| 2011 | 8.44262 |
| 2010 | 8.37761 |
| 2009 | 8.35334 |
| 2008 | 8.35902 |
| 2007 | 8.33912 |
| 2006 | 8.30381 |
| 2005 | 8.31855 |
| 2004 | 8.28719 |
| 2003 | 8.16215 |
| 2002 | 8.1845 |
| 2001 | 8.383 |
| 2000 | 8.56631 |
| 1999 | 8.69035 |
| 1998 | 8.81222 |
| 1997 | 8.93172 |
| 1996 | 9.00472 |
| 1995 | 8.8942 |
| 1994 | 8.73003 |
| 1993 | 8.80109 |
| 1992 | 8.8642 |
| 1991 | 8.70403 |
| 1990 | 8.62058 |
| 1989 | 8.65038 |
| 1988 | 8.60698 |
| 1987 | 8.53247 |
| 1986 | 8.40498 |
| 1985 | 8.31722 |
| 1984 | 8.47933 |
| 1983 | 8.61658 |
| 1982 | 8.26033 |
| 1981 | 7.85699 |
| 1980 | 8.05287 |
| 1979 | 8.28307 |
| 1978 | 8.29338 |
| 1977 | 8.3487 |
| 1976 | 8.40912 |
| 1975 | 8.46362 |
| 1974 | 8.37351 |
| 1973 | 8.18376 |
| 1972 | 8.03549 |
| 1971 | 7.88509 |
| 1970 | 7.73542 |
| 1969 | 7.73712 |
| 1968 | 7.83527 |
| 1967 | 7.8745 |
| 1966 | 7.90274 |
| 1965 | 7.91677 |
| 1964 | 7.93198 |
| 1963 | 7.95845 |
| 1962 | 7.99823 |
| 1961 | 8.04653 |
| 1960 | 8.09572 |