| 年份 | 乍得 |
|---|---|
| 2023 | - |
| 2022 | 2.65174 |
| 2021 | 2.62385 |
| 2020 | 2.60512 |
| 2019 | 2.58694 |
| 2018 | 2.56956 |
| 2017 | 2.55258 |
| 2016 | 2.5343 |
| 2015 | 2.51394 |
| 2014 | 2.49196 |
| 2013 | 2.4695 |
| 2012 | 2.44673 |
| 2011 | 2.42497 |
| 2010 | 2.40577 |
| 2009 | 2.38967 |
| 2008 | 2.37755 |
| 2007 | 2.37001 |
| 2006 | 2.36728 |
| 2005 | 2.37012 |
| 2004 | 2.33763 |
| 2003 | 2.27992 |
| 2002 | 2.23819 |
| 2001 | 2.20072 |
| 2000 | 2.16803 |
| 1999 | 2.18977 |
| 1998 | 2.24941 |
| 1997 | 2.29247 |
| 1996 | 2.33564 |
| 1995 | 2.37908 |
| 1994 | 2.42747 |
| 1993 | 2.4809 |
| 1992 | 2.54083 |
| 1991 | 2.60886 |
| 1990 | 2.677 |
| 1989 | 2.74161 |
| 1988 | 2.80748 |
| 1987 | 2.8732 |
| 1986 | 2.93886 |
| 1985 | 2.99953 |
| 1984 | 3.04383 |
| 1983 | 3.08526 |
| 1982 | 3.15298 |
| 1981 | 3.22097 |
| 1980 | 3.24907 |
| 1979 | 3.27834 |
| 1978 | 3.3274 |
| 1977 | 3.37392 |
| 1976 | 3.41613 |
| 1975 | 3.45185 |
| 1974 | 3.48212 |
| 1973 | 3.5069 |
| 1972 | 3.52706 |
| 1971 | 3.54436 |
| 1970 | 3.56105 |
| 1969 | 3.57822 |
| 1968 | 3.59551 |
| 1967 | 3.61455 |
| 1966 | 3.63543 |
| 1965 | 3.65819 |
| 1964 | 3.68428 |
| 1963 | 3.71536 |
| 1962 | 3.7487 |
| 1961 | 3.77832 |
| 1960 | 3.80049 |