| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | 1.49371 |
| 2021 | 1.50256 |
| 2020 | 1.51151 |
| 2019 | 1.51596 |
| 2018 | 1.51571 |
| 2017 | 1.51566 |
| 2016 | 1.51547 |
| 2015 | 1.51436 |
| 2014 | 1.47309 |
| 2013 | 1.39865 |
| 2012 | 1.34017 |
| 2011 | 1.2948 |
| 2010 | 1.25696 |
| 2009 | 1.27526 |
| 2008 | 1.33712 |
| 2007 | 1.37299 |
| 2006 | 1.38647 |
| 2005 | 1.38618 |
| 2004 | 1.37854 |
| 2003 | 1.36638 |
| 2002 | 1.3523 |
| 2001 | 1.33923 |
| 2000 | 1.32724 |
| 1999 | 1.31538 |
| 1998 | 1.30542 |
| 1997 | 1.29801 |
| 1996 | 1.29102 |
| 1995 | 1.28339 |
| 1994 | 1.27523 |
| 1993 | 1.26653 |
| 1992 | 1.25784 |
| 1991 | 1.251 |
| 1990 | 1.2471 |
| 1989 | 1.24573 |
| 1988 | 1.24685 |
| 1987 | 1.25019 |
| 1986 | 1.2536 |
| 1985 | 1.25568 |
| 1984 | 1.25675 |
| 1983 | 1.25625 |
| 1982 | 1.25426 |
| 1981 | 1.25244 |
| 1980 | 1.25155 |
| 1979 | 1.25123 |
| 1978 | 1.25096 |
| 1977 | 1.25071 |
| 1976 | 1.25001 |
| 1975 | 1.24858 |
| 1974 | 1.24635 |
| 1973 | 1.24293 |
| 1972 | 1.2385 |
| 1971 | 1.23441 |
| 1970 | 1.23069 |
| 1969 | 1.22693 |
| 1968 | 1.2242 |
| 1967 | 1.22053 |
| 1966 | 1.21006 |
| 1965 | 1.18863 |
| 1964 | 1.15573 |
| 1963 | 1.10906 |
| 1962 | 1.05202 |
| 1961 | 0.997909 |
| 1960 | 0.955951 |