| 年份 | 乍得 |
|---|---|
| 2023 | - |
| 2022 | 18.8432 |
| 2021 | 18.9278 |
| 2020 | 19.0535 |
| 2019 | 19.2029 |
| 2018 | 19.39 |
| 2017 | 19.6072 |
| 2016 | 19.8086 |
| 2015 | 19.9393 |
| 2014 | 20.0218 |
| 2013 | 20.1329 |
| 2012 | 20.2327 |
| 2011 | 20.3148 |
| 2010 | 20.3888 |
| 2009 | 20.4265 |
| 2008 | 20.428 |
| 2007 | 20.3706 |
| 2006 | 20.309 |
| 2005 | 20.2834 |
| 2004 | 20.3484 |
| 2003 | 20.5672 |
| 2002 | 20.7735 |
| 2001 | 20.8907 |
| 2000 | 20.9175 |
| 1999 | 20.879 |
| 1998 | 20.8936 |
| 1997 | 20.9431 |
| 1996 | 20.8899 |
| 1995 | 20.9934 |
| 1994 | 21.1976 |
| 1993 | 20.9394 |
| 1992 | 20.5354 |
| 1991 | 20.4322 |
| 1990 | 20.2348 |
| 1989 | 19.9507 |
| 1988 | 19.8643 |
| 1987 | 19.6694 |
| 1986 | 19.4414 |
| 1985 | 19.3399 |
| 1984 | 18.9766 |
| 1983 | 18.5769 |
| 1982 | 18.9252 |
| 1981 | 19.5504 |
| 1980 | 19.4453 |
| 1979 | 19.2241 |
| 1978 | 19.2755 |
| 1977 | 19.263 |
| 1976 | 19.1593 |
| 1975 | 18.9688 |
| 1974 | 18.7493 |
| 1973 | 18.4919 |
| 1972 | 18.1875 |
| 1971 | 17.924 |
| 1970 | 17.7397 |
| 1969 | 17.583 |
| 1968 | 17.4609 |
| 1967 | 17.3685 |
| 1966 | 17.2981 |
| 1965 | 17.2523 |
| 1964 | 17.2264 |
| 1963 | 17.2081 |
| 1962 | 17.1917 |
| 1961 | 17.1746 |
| 1960 | 17.1564 |