| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | - |
| 2021 | 0.700915 |
| 2020 | 0.727388 |
| 2019 | 0.75501 |
| 2018 | 0.783982 |
| 2017 | 0.814245 |
| 2016 | 0.83645 |
| 2015 | 0.834653 |
| 2014 | 0.86723 |
| 2013 | 0.90065 |
| 2012 | 0.885576 |
| 2011 | 0.902615 |
| 2010 | 0.907041 |
| 2009 | 0.929048 |
| 2008 | 0.965372 |
| 2007 | 1.00182 |
| 2006 | 0.984117 |
| 2005 | 1.01933 |
| 2004 | 1.05522 |
| 2003 | 1.08908 |
| 2002 | 1.1207 |
| 2001 | 1.16113 |
| 2000 | 1.20239 |
| 1999 | 1.24507 |
| 1998 | 1.28826 |
| 1997 | 1.33264 |
| 1996 | 1.37784 |
| 1995 | 1.42502 |
| 1994 | 1.3678 |
| 1993 | 1.41258 |
| 1992 | 1.45796 |
| 1991 | 1.40041 |
| 1990 | 1.31842 |
| 1989 | 1.1821 |
| 1988 | 1.20537 |
| 1987 | 1.24427 |
| 1986 | 1.31878 |
| 1985 | 1.35928 |
| 1984 | 1.40123 |
| 1983 | 1.47814 |
| 1982 | 1.50081 |
| 1981 | 1.53497 |
| 1980 | 1.65425 |
| 1979 | 1.66223 |
| 1978 | 1.68217 |
| 1977 | 1.73153 |
| 1976 | 1.78076 |
| 1975 | 1.83088 |
| 1974 | 1.88124 |
| 1973 | 2.13662 |
| 1972 | 2.26802 |
| 1971 | 2.34018 |
| 1970 | 2.39779 |
| 1969 | 2.67951 |
| 1968 | 2.7558 |
| 1967 | 2.67751 |
| 1966 | 2.75566 |
| 1965 | 2.83654 |
| 1964 | 2.92075 |
| 1963 | 3.00809 |
| 1962 | 3.09857 |
| 1961 | 3.19192 |
| 1960 | - |