| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | 2.00182 |
| 2021 | 2.01967 |
| 2020 | 2.0359 |
| 2019 | 2.04774 |
| 2018 | 2.05516 |
| 2017 | 2.06123 |
| 2016 | 2.06619 |
| 2015 | 2.0705 |
| 2014 | 2.07389 |
| 2013 | 2.07667 |
| 2012 | 2.0798 |
| 2011 | 2.08232 |
| 2010 | 2.08284 |
| 2009 | 2.07649 |
| 2008 | 2.06855 |
| 2007 | 2.08272 |
| 2006 | 2.12314 |
| 2005 | 2.17671 |
| 2004 | 2.24411 |
| 2003 | 2.31521 |
| 2002 | 2.35695 |
| 2001 | 2.36417 |
| 2000 | 2.3554 |
| 1999 | 2.33872 |
| 1998 | 2.31915 |
| 1997 | 2.29926 |
| 1996 | 2.27995 |
| 1995 | 2.26138 |
| 1994 | 2.2427 |
| 1993 | 2.22459 |
| 1992 | 2.20812 |
| 1991 | 2.19266 |
| 1990 | 2.17795 |
| 1989 | 2.16361 |
| 1988 | 2.14862 |
| 1987 | 2.13406 |
| 1986 | 2.12288 |
| 1985 | 2.11689 |
| 1984 | 2.11552 |
| 1983 | 2.11777 |
| 1982 | 2.12347 |
| 1981 | 2.13116 |
| 1980 | 2.1392 |
| 1979 | 2.14733 |
| 1978 | 2.15535 |
| 1977 | 2.16192 |
| 1976 | 2.16609 |
| 1975 | 2.16737 |
| 1974 | 2.16602 |
| 1973 | 2.16224 |
| 1972 | 2.15612 |
| 1971 | 2.14875 |
| 1970 | 2.14056 |
| 1969 | 2.13103 |
| 1968 | 2.1205 |
| 1967 | 2.10849 |
| 1966 | 2.09246 |
| 1965 | 2.07083 |
| 1964 | 2.04365 |
| 1963 | 2.009 |
| 1962 | 1.97135 |
| 1961 | 1.94336 |
| 1960 | 1.93125 |