| 年份 | 乍得 |
|---|---|
| 2023 | - |
| 2022 | 2.0119 |
| 2021 | 1.9989 |
| 2020 | 1.98401 |
| 2019 | 1.96486 |
| 2018 | 1.94313 |
| 2017 | 1.92139 |
| 2016 | 1.90053 |
| 2015 | 1.88132 |
| 2014 | 1.86543 |
| 2013 | 1.85484 |
| 2012 | 1.84812 |
| 2011 | 1.84513 |
| 2010 | 1.84666 |
| 2009 | 1.82082 |
| 2008 | 1.77653 |
| 2007 | 1.74442 |
| 2006 | 1.71493 |
| 2005 | 1.68918 |
| 2004 | 1.7064 |
| 2003 | 1.75422 |
| 2002 | 1.78845 |
| 2001 | 1.82152 |
| 2000 | 1.85389 |
| 1999 | 1.89034 |
| 1998 | 1.93329 |
| 1997 | 1.98191 |
| 1996 | 2.03466 |
| 1995 | 2.09528 |
| 1994 | 2.15718 |
| 1993 | 2.20497 |
| 1992 | 2.25247 |
| 1991 | 2.3148 |
| 1990 | 2.37356 |
| 1989 | 2.42359 |
| 1988 | 2.47658 |
| 1987 | 2.529 |
| 1986 | 2.58311 |
| 1985 | 2.63199 |
| 1984 | 2.65878 |
| 1983 | 2.69011 |
| 1982 | 2.76726 |
| 1981 | 2.83951 |
| 1980 | 2.84282 |
| 1979 | 2.84098 |
| 1978 | 2.85871 |
| 1977 | 2.86731 |
| 1976 | 2.87642 |
| 1975 | 2.89036 |
| 1974 | 2.90874 |
| 1973 | 2.93077 |
| 1972 | 2.95662 |
| 1971 | 2.98263 |
| 1970 | 3.00702 |
| 1969 | 3.03228 |
| 1968 | 3.05969 |
| 1967 | 3.08741 |
| 1966 | 3.11152 |
| 1965 | 3.12975 |
| 1964 | 3.14188 |
| 1963 | 3.1459 |
| 1962 | 3.14558 |
| 1961 | 3.15175 |
| 1960 | 3.17191 |