| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | 3.75873 |
| 2021 | 3.75381 |
| 2020 | 3.74216 |
| 2019 | 3.72939 |
| 2018 | 3.71858 |
| 2017 | 3.71366 |
| 2016 | 3.71559 |
| 2015 | 3.72309 |
| 2014 | 3.73931 |
| 2013 | 3.76647 |
| 2012 | 3.80278 |
| 2011 | 3.84725 |
| 2010 | 3.89761 |
| 2009 | 3.94957 |
| 2008 | 4.00004 |
| 2007 | 4.04471 |
| 2006 | 4.08235 |
| 2005 | 4.11448 |
| 2004 | 4.14021 |
| 2003 | 4.15918 |
| 2002 | 4.17328 |
| 2001 | 4.1829 |
| 2000 | 4.18912 |
| 1999 | 4.19358 |
| 1998 | 4.19679 |
| 1997 | 4.19931 |
| 1996 | 4.19906 |
| 1995 | 4.1921 |
| 1994 | 4.06775 |
| 1993 | 3.85107 |
| 1992 | 3.68425 |
| 1991 | 3.5577 |
| 1990 | 3.45443 |
| 1989 | 3.49725 |
| 1988 | 3.64975 |
| 1987 | 3.73373 |
| 1986 | 3.75983 |
| 1985 | 3.75215 |
| 1984 | 3.72906 |
| 1983 | 3.69641 |
| 1982 | 3.66029 |
| 1981 | 3.62911 |
| 1980 | 3.60251 |
| 1979 | 3.57678 |
| 1978 | 3.55559 |
| 1977 | 3.54091 |
| 1976 | 3.5279 |
| 1975 | 3.51462 |
| 1974 | 3.50256 |
| 1973 | 3.49164 |
| 1972 | 3.48258 |
| 1971 | 3.48096 |
| 1970 | 3.49001 |
| 1969 | 3.50852 |
| 1968 | 3.53636 |
| 1967 | 3.57176 |
| 1966 | 3.6082 |
| 1965 | 3.64079 |
| 1964 | 3.67028 |
| 1963 | 3.69692 |
| 1962 | 3.72055 |
| 1961 | 3.74476 |
| 1960 | 3.77211 |