| 年份 | 乍得 |
|---|---|
| 2023 | - |
| 2022 | 1.84397 |
| 2021 | 1.83296 |
| 2020 | 1.82029 |
| 2019 | 1.80324 |
| 2018 | 1.78273 |
| 2017 | 1.76161 |
| 2016 | 1.74107 |
| 2015 | 1.72282 |
| 2014 | 1.70742 |
| 2013 | 1.69457 |
| 2012 | 1.68483 |
| 2011 | 1.6782 |
| 2010 | 1.67523 |
| 2009 | 1.6511 |
| 2008 | 1.61468 |
| 2007 | 1.59262 |
| 2006 | 1.57517 |
| 2005 | 1.56142 |
| 2004 | 1.58197 |
| 2003 | 1.62309 |
| 2002 | 1.65084 |
| 2001 | 1.67891 |
| 2000 | 1.70686 |
| 1999 | 1.73777 |
| 1998 | 1.77415 |
| 1997 | 1.81526 |
| 1996 | 1.85822 |
| 1995 | 1.90096 |
| 1994 | 1.94151 |
| 1993 | 1.97639 |
| 1992 | 2.00899 |
| 1991 | 2.04633 |
| 1990 | 2.08679 |
| 1989 | 2.12726 |
| 1988 | 2.17048 |
| 1987 | 2.218 |
| 1986 | 2.26669 |
| 1985 | 2.31069 |
| 1984 | 2.3448 |
| 1983 | 2.38013 |
| 1982 | 2.43615 |
| 1981 | 2.4912 |
| 1980 | 2.51435 |
| 1979 | 2.53722 |
| 1978 | 2.57392 |
| 1977 | 2.60794 |
| 1976 | 2.63926 |
| 1975 | 2.66665 |
| 1974 | 2.6906 |
| 1973 | 2.71091 |
| 1972 | 2.72817 |
| 1971 | 2.74298 |
| 1970 | 2.75562 |
| 1969 | 2.7668 |
| 1968 | 2.77672 |
| 1967 | 2.78741 |
| 1966 | 2.80058 |
| 1965 | 2.81691 |
| 1964 | 2.83685 |
| 1963 | 2.86135 |
| 1962 | 2.88912 |
| 1961 | 2.91654 |
| 1960 | 2.94136 |