| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | 2.39643 |
| 2021 | 2.42551 |
| 2020 | 2.45728 |
| 2019 | 2.48826 |
| 2018 | 2.51661 |
| 2017 | 2.54168 |
| 2016 | 2.56282 |
| 2015 | 2.58072 |
| 2014 | 2.59472 |
| 2013 | 2.60506 |
| 2012 | 2.613 |
| 2011 | 2.61912 |
| 2010 | 2.62434 |
| 2009 | 2.62901 |
| 2008 | 2.63339 |
| 2007 | 2.63762 |
| 2006 | 2.64071 |
| 2005 | 2.64164 |
| 2004 | 2.57077 |
| 2003 | 2.44157 |
| 2002 | 2.34261 |
| 2001 | 2.26813 |
| 2000 | 2.20742 |
| 1999 | 2.24155 |
| 1998 | 2.34753 |
| 1997 | 2.40784 |
| 1996 | 2.42872 |
| 1995 | 2.42464 |
| 1994 | 2.40634 |
| 1993 | 2.37925 |
| 1992 | 2.3484 |
| 1991 | 2.31922 |
| 1990 | 2.29249 |
| 1989 | 2.26659 |
| 1988 | 2.24445 |
| 1987 | 2.22831 |
| 1986 | 2.21487 |
| 1985 | 2.20261 |
| 1984 | 2.19273 |
| 1983 | 2.18407 |
| 1982 | 2.17684 |
| 1981 | 2.17461 |
| 1980 | 2.17888 |
| 1979 | 2.18823 |
| 1978 | 2.20187 |
| 1977 | 2.2183 |
| 1976 | 2.23375 |
| 1975 | 2.24609 |
| 1974 | 2.25576 |
| 1973 | 2.26292 |
| 1972 | 2.26773 |
| 1971 | 2.27279 |
| 1970 | 2.27956 |
| 1969 | 2.28737 |
| 1968 | 2.29605 |
| 1967 | 2.30571 |
| 1966 | 2.31502 |
| 1965 | 2.3226 |
| 1964 | 2.32839 |
| 1963 | 2.33202 |
| 1962 | 2.33358 |
| 1961 | 2.33509 |
| 1960 | 2.33752 |