| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | 4.42469 |
| 2021 | 4.45618 |
| 2020 | 4.48752 |
| 2019 | 4.51123 |
| 2018 | 4.52738 |
| 2017 | 4.53195 |
| 2016 | 4.52184 |
| 2015 | 4.5028 |
| 2014 | 4.48478 |
| 2013 | 4.47456 |
| 2012 | 4.47377 |
| 2011 | 4.48584 |
| 2010 | 4.51104 |
| 2009 | 4.54541 |
| 2008 | 4.58862 |
| 2007 | 4.63942 |
| 2006 | 4.69429 |
| 2005 | 4.74971 |
| 2004 | 4.80484 |
| 2003 | 4.85684 |
| 2002 | 4.9007 |
| 2001 | 4.93534 |
| 2000 | 4.96319 |
| 1999 | 4.98449 |
| 1998 | 4.99839 |
| 1997 | 5.00714 |
| 1996 | 5.01078 |
| 1995 | 5.00655 |
| 1994 | 4.99609 |
| 1993 | 4.98281 |
| 1992 | 4.9677 |
| 1991 | 4.94899 |
| 1990 | 4.9247 |
| 1989 | 4.88265 |
| 1988 | 4.83729 |
| 1987 | 4.84691 |
| 1986 | 4.91952 |
| 1985 | 5.02388 |
| 1984 | 5.16207 |
| 1983 | 5.30829 |
| 1982 | 5.38877 |
| 1981 | 5.39448 |
| 1980 | 5.36537 |
| 1979 | 5.3182 |
| 1978 | 5.26331 |
| 1977 | 5.20676 |
| 1976 | 5.15159 |
| 1975 | 5.09836 |
| 1974 | 5.04781 |
| 1973 | 5.00292 |
| 1972 | 4.96441 |
| 1971 | 4.93024 |
| 1970 | 4.89968 |
| 1969 | 4.87244 |
| 1968 | 4.84589 |
| 1967 | 4.82148 |
| 1966 | 4.80498 |
| 1965 | 4.79919 |
| 1964 | 4.80319 |
| 1963 | 4.81662 |
| 1962 | 4.83846 |
| 1961 | 4.86476 |
| 1960 | 4.89305 |