| 年份 | 乍得  | 
                                                            
|---|---|
| 2023 | - | 
| 2022 | 2.50378 | 
| 2021 | 2.47587 | 
| 2020 | 2.45585 | 
| 2019 | 2.43582 | 
| 2018 | 2.41586 | 
| 2017 | 2.39652 | 
| 2016 | 2.37723 | 
| 2015 | 2.35805 | 
| 2014 | 2.33811 | 
| 2013 | 2.31592 | 
| 2012 | 2.29334 | 
| 2011 | 2.27168 | 
| 2010 | 2.25195 | 
| 2009 | 2.23494 | 
| 2008 | 2.22031 | 
| 2007 | 2.20975 | 
| 2006 | 2.20305 | 
| 2005 | 2.19979 | 
| 2004 | 2.16525 | 
| 2003 | 2.11081 | 
| 2002 | 2.07749 | 
| 2001 | 2.05419 | 
| 2000 | 2.03785 | 
| 1999 | 2.06804 | 
| 1998 | 2.12668 | 
| 1997 | 2.16693 | 
| 1996 | 2.20602 | 
| 1995 | 2.23943 | 
| 1994 | 2.27672 | 
| 1993 | 2.33118 | 
| 1992 | 2.3909 | 
| 1991 | 2.44441 | 
| 1990 | 2.49791 | 
| 1989 | 2.54947 | 
| 1988 | 2.59343 | 
| 1987 | 2.63473 | 
| 1986 | 2.67581 | 
| 1985 | 2.71818 | 
| 1984 | 2.76315 | 
| 1983 | 2.80926 | 
| 1982 | 2.86005 | 
| 1981 | 2.91204 | 
| 1980 | 2.95571 | 
| 1979 | 2.99837 | 
| 1978 | 3.04482 | 
| 1977 | 3.08971 | 
| 1976 | 3.13483 | 
| 1975 | 3.18067 | 
| 1974 | 3.2273 | 
| 1973 | 3.27562 | 
| 1972 | 3.32469 | 
| 1971 | 3.36771 | 
| 1970 | 3.40033 | 
| 1969 | 3.42469 | 
| 1968 | 3.44052 | 
| 1967 | 3.4492 | 
| 1966 | 3.45578 | 
| 1965 | 3.46302 | 
| 1964 | 3.47063 | 
| 1963 | 3.47875 | 
| 1962 | 3.48927 | 
| 1961 | 3.50376 | 
| 1960 | 3.52307 |