| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | 3.54106 |
| 2021 | 3.55739 |
| 2020 | 3.59645 |
| 2019 | 3.65531 |
| 2018 | 3.69789 |
| 2017 | 3.75523 |
| 2016 | 3.81573 |
| 2015 | 3.79544 |
| 2014 | 3.76805 |
| 2013 | 3.82298 |
| 2012 | 3.81535 |
| 2011 | 3.75269 |
| 2010 | 3.73548 |
| 2009 | 3.70594 |
| 2008 | 3.67852 |
| 2007 | 3.64598 |
| 2006 | 3.6192 |
| 2005 | 3.59415 |
| 2004 | 3.55395 |
| 2003 | 3.50924 |
| 2002 | 3.47813 |
| 2001 | 3.3682 |
| 2000 | 3.32476 |
| 1999 | 3.31123 |
| 1998 | 3.28078 |
| 1997 | 3.23804 |
| 1996 | 3.26918 |
| 1995 | 3.22397 |
| 1994 | 3.11777 |
| 1993 | 3.05817 |
| 1992 | 3.01812 |
| 1991 | 3.00931 |
| 1990 | 2.99517 |
| 1989 | 2.95585 |
| 1988 | 2.78486 |
| 1987 | 2.76397 |
| 1986 | 2.75901 |
| 1985 | 2.75749 |
| 1984 | 2.75803 |
| 1983 | 2.77857 |
| 1982 | 2.81624 |
| 1981 | 2.83349 |
| 1980 | 2.81748 |
| 1979 | 2.75802 |
| 1978 | 2.45982 |
| 1977 | 2.08817 |
| 1976 | 2.0733 |
| 1975 | 2.06719 |
| 1974 | 2.06173 |
| 1973 | 2.08281 |
| 1972 | 2.10496 |
| 1971 | 2.16647 |
| 1970 | 2.25342 |
| 1969 | 2.31965 |
| 1968 | 2.39178 |
| 1967 | 2.45297 |
| 1966 | 2.58013 |
| 1965 | 2.61656 |
| 1964 | 2.65806 |
| 1963 | 2.68772 |
| 1962 | 2.85775 |
| 1961 | 2.85137 |
| 1960 | - |