| 年份 | 乍得 |
|---|---|
| 2023 | - |
| 2022 | - |
| 2021 | 2.24479 |
| 2020 | 2.24479 |
| 2019 | 2.35432 |
| 2018 | 3.00814 |
| 2017 | 3.06158 |
| 2016 | 2.4093 |
| 2015 | 2.44478 |
| 2014 | 2.48328 |
| 2013 | 2.47014 |
| 2012 | 2.42416 |
| 2011 | 2.75835 |
| 2010 | 4.03333 |
| 2009 | 3.27844 |
| 2008 | 3.64877 |
| 2007 | 3.32623 |
| 2006 | 3.41608 |
| 2005 | 3.54269 |
| 2004 | 2.32953 |
| 2003 | 2.73139 |
| 2002 | 3.11505 |
| 2001 | 4.72973 |
| 2000 | 4.86111 |
| 1999 | 4.86111 |
| 1998 | 4.67222 |
| 1997 | 2.18056 |
| 1996 | 3.5 |
| 1995 | 2.50234 |
| 1994 | 2.0649 |
| 1993 | 1.55846 |
| 1992 | 3.01496 |
| 1991 | 2.5888 |
| 1990 | 1.77207 |
| 1989 | 1.52405 |
| 1988 | 1.52263 |
| 1987 | 1.69811 |
| 1986 | 1.32075 |
| 1985 | 2.26837 |
| 1984 | 2.23857 |
| 1983 | 1.85304 |
| 1982 | 1.72414 |
| 1981 | 1.4673 |
| 1980 | 0.286898 |
| 1979 | - |
| 1978 | 2.22717 |
| 1977 | 2.44265 |
| 1976 | 2.61712 |
| 1975 | 1.96864 |
| 1974 | 3.05108 |
| 1973 | 1.64155 |
| 1972 | 0.85088 |
| 1971 | 0.770452 |
| 1970 | 0.658612 |
| 1969 | 0.608906 |
| 1968 | 0.483259 |
| 1967 | 0.387297 |
| 1966 | 0.165689 |
| 1965 | 0.15982 |
| 1964 | 0.0265792 |
| 1963 | 0.0559199 |
| 1962 | 0.0479807 |
| 1961 | 0.0590266 |
| 1960 | - |