| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | 0.763338 |
| 2021 | 0.781282 |
| 2020 | 0.805311 |
| 2019 | 0.831258 |
| 2018 | 0.855175 |
| 2017 | 0.868215 |
| 2016 | 0.867977 |
| 2015 | 0.861913 |
| 2014 | 0.852826 |
| 2013 | 0.842744 |
| 2012 | 0.833228 |
| 2011 | 0.824414 |
| 2010 | 0.815783 |
| 2009 | 0.807789 |
| 2008 | 0.80086 |
| 2007 | 0.795013 |
| 2006 | 0.790045 |
| 2005 | 0.785885 |
| 2004 | 0.782328 |
| 2003 | 0.779119 |
| 2002 | 0.775998 |
| 2001 | 0.773316 |
| 2000 | 0.771635 |
| 1999 | 0.770501 |
| 1998 | 0.769918 |
| 1997 | 0.769864 |
| 1996 | 0.769616 |
| 1995 | 0.768853 |
| 1994 | 0.767373 |
| 1993 | 0.7653 |
| 1992 | 0.762737 |
| 1991 | 0.759362 |
| 1990 | 0.75473 |
| 1989 | 0.748759 |
| 1988 | 0.741562 |
| 1987 | 0.733362 |
| 1986 | 0.724848 |
| 1985 | 0.716343 |
| 1984 | 0.707522 |
| 1983 | 0.697736 |
| 1982 | 0.68689 |
| 1981 | 0.67481 |
| 1980 | 0.661148 |
| 1979 | 0.645606 |
| 1978 | 0.627736 |
| 1977 | 0.609149 |
| 1976 | 0.593496 |
| 1975 | 0.582368 |
| 1974 | 0.576704 |
| 1973 | 0.578936 |
| 1972 | 0.587274 |
| 1971 | 0.595019 |
| 1970 | 0.597362 |
| 1969 | 0.594051 |
| 1968 | 0.584397 |
| 1967 | 0.56733 |
| 1966 | 0.543927 |
| 1965 | 0.51489 |
| 1964 | 0.478434 |
| 1963 | 0.431568 |
| 1962 | 0.378055 |
| 1961 | 0.327625 |
| 1960 | 0.286595 |