| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | 0.602025 |
| 2021 | 0.586109 |
| 2020 | 0.572135 |
| 2019 | 0.581261 |
| 2018 | 0.608389 |
| 2017 | 0.623378 |
| 2016 | 0.628006 |
| 2015 | 0.626206 |
| 2014 | 0.620649 |
| 2013 | 0.612817 |
| 2012 | 0.604132 |
| 2011 | 0.596044 |
| 2010 | 0.588693 |
| 2009 | 0.581648 |
| 2008 | 0.575777 |
| 2007 | 0.571476 |
| 2006 | 0.567802 |
| 2005 | 0.564239 |
| 2004 | 0.560991 |
| 2003 | 0.55783 |
| 2002 | 0.554822 |
| 2001 | 0.55272 |
| 2000 | 0.55175 |
| 1999 | 0.551648 |
| 1998 | 0.552452 |
| 1997 | 0.553765 |
| 1996 | 0.5545 |
| 1995 | 0.553961 |
| 1994 | 0.552121 |
| 1993 | 0.549071 |
| 1992 | 0.544937 |
| 1991 | 0.540273 |
| 1990 | 0.535249 |
| 1989 | 0.52986 |
| 1988 | 0.524237 |
| 1987 | 0.51857 |
| 1986 | 0.512719 |
| 1985 | 0.506553 |
| 1984 | 0.500097 |
| 1983 | 0.492956 |
| 1982 | 0.485276 |
| 1981 | 0.477723 |
| 1980 | 0.470636 |
| 1979 | 0.464068 |
| 1978 | 0.458189 |
| 1977 | 0.452527 |
| 1976 | 0.445295 |
| 1975 | 0.435062 |
| 1974 | 0.421368 |
| 1973 | 0.403039 |
| 1972 | 0.380892 |
| 1971 | 0.359562 |
| 1970 | 0.342238 |
| 1969 | 0.329007 |
| 1968 | 0.321481 |
| 1967 | 0.319086 |
| 1966 | 0.316187 |
| 1965 | 0.308773 |
| 1964 | 0.297058 |
| 1963 | 0.280264 |
| 1962 | 0.258619 |
| 1961 | 0.237768 |
| 1960 | 0.222099 |