| 年份 | 乍得 |
|---|---|
| 2023 | - |
| 2022 | 0.168469 |
| 2021 | 0.176627 |
| 2020 | 0.184733 |
| 2019 | 0.190437 |
| 2018 | 0.192399 |
| 2017 | 0.193363 |
| 2016 | 0.194916 |
| 2015 | 0.199101 |
| 2014 | 0.204707 |
| 2013 | 0.207949 |
| 2012 | 0.211599 |
| 2011 | 0.216186 |
| 2010 | 0.221285 |
| 2009 | 0.227671 |
| 2008 | 0.233613 |
| 2007 | 0.240632 |
| 2006 | 0.248838 |
| 2005 | 0.256759 |
| 2004 | 0.261173 |
| 2003 | 0.259933 |
| 2002 | 0.259917 |
| 2001 | 0.263285 |
| 2000 | 0.267707 |
| 1999 | 0.271486 |
| 1998 | 0.274696 |
| 1997 | 0.278323 |
| 1996 | 0.282638 |
| 1995 | 0.278161 |
| 1994 | 0.270188 |
| 1993 | 0.27812 |
| 1992 | 0.288911 |
| 1991 | 0.285487 |
| 1990 | 0.283414 |
| 1989 | 0.288522 |
| 1988 | 0.289617 |
| 1987 | 0.289193 |
| 1986 | 0.284437 |
| 1985 | 0.279582 |
| 1984 | 0.290051 |
| 1983 | 0.304188 |
| 1982 | 0.288955 |
| 1981 | 0.265443 |
| 1980 | 0.268899 |
| 1979 | 0.273785 |
| 1978 | 0.27079 |
| 1977 | 0.269553 |
| 1976 | 0.26942 |
| 1975 | 0.270694 |
| 1974 | 0.273086 |
| 1973 | 0.27666 |
| 1972 | 0.281782 |
| 1971 | 0.287592 |
| 1970 | 0.293035 |
| 1969 | 0.298204 |
| 1968 | 0.303139 |
| 1967 | 0.307873 |
| 1966 | 0.312572 |
| 1965 | 0.316715 |
| 1964 | 0.319656 |
| 1963 | 0.320811 |
| 1962 | 0.320113 |
| 1961 | 0.318604 |
| 1960 | 0.31761 |