| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | 8.70043 |
| 2021 | 8.65401 |
| 2020 | 8.60492 |
| 2019 | 8.55169 |
| 2018 | 8.4922 |
| 2017 | 8.42526 |
| 2016 | 8.35261 |
| 2015 | 8.27947 |
| 2014 | 8.22156 |
| 2013 | 8.18494 |
| 2012 | 8.16481 |
| 2011 | 8.16602 |
| 2010 | 8.19709 |
| 2009 | 8.25772 |
| 2008 | 8.3358 |
| 2007 | 8.41889 |
| 2006 | 8.51228 |
| 2005 | 8.60579 |
| 2004 | 8.68076 |
| 2003 | 8.73747 |
| 2002 | 8.7694 |
| 2001 | 8.7696 |
| 2000 | 8.74993 |
| 1999 | 8.72548 |
| 1998 | 8.70351 |
| 1997 | 8.69487 |
| 1996 | 8.70154 |
| 1995 | 8.71064 |
| 1994 | 8.72808 |
| 1993 | 8.76407 |
| 1992 | 8.81831 |
| 1991 | 8.8853 |
| 1990 | 8.95674 |
| 1989 | 9.0276 |
| 1988 | 9.09402 |
| 1987 | 9.15202 |
| 1986 | 9.19964 |
| 1985 | 9.24331 |
| 1984 | 9.28544 |
| 1983 | 9.32134 |
| 1982 | 9.35274 |
| 1981 | 9.38121 |
| 1980 | 9.40516 |
| 1979 | 9.42275 |
| 1978 | 9.43444 |
| 1977 | 9.44097 |
| 1976 | 9.44012 |
| 1975 | 9.43056 |
| 1974 | 9.16773 |
| 1973 | 8.70572 |
| 1972 | 8.35695 |
| 1971 | 8.09945 |
| 1970 | 7.89667 |
| 1969 | 8.02059 |
| 1968 | 8.38941 |
| 1967 | 8.60942 |
| 1966 | 8.70269 |
| 1965 | 8.71851 |
| 1964 | 8.69562 |
| 1963 | 8.65114 |
| 1962 | 8.59929 |
| 1961 | 8.55846 |
| 1960 | 8.53237 |