| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | 2.4038 |
| 2021 | 2.41935 |
| 2020 | 2.43561 |
| 2019 | 2.43637 |
| 2018 | 2.42164 |
| 2017 | 2.40661 |
| 2016 | 2.3915 |
| 2015 | 2.3766 |
| 2014 | 2.38303 |
| 2013 | 2.40607 |
| 2012 | 2.4123 |
| 2011 | 2.40219 |
| 2010 | 2.38383 |
| 2009 | 2.36195 |
| 2008 | 2.33975 |
| 2007 | 2.31898 |
| 2006 | 2.30078 |
| 2005 | 2.28507 |
| 2004 | 2.27146 |
| 2003 | 2.26081 |
| 2002 | 2.25288 |
| 2001 | 2.24587 |
| 2000 | 2.23885 |
| 1999 | 2.23131 |
| 1998 | 2.22272 |
| 1997 | 2.21295 |
| 1996 | 2.2029 |
| 1995 | 2.19245 |
| 1994 | 2.18075 |
| 1993 | 2.1685 |
| 1992 | 2.15616 |
| 1991 | 2.14236 |
| 1990 | 2.12562 |
| 1989 | 2.10649 |
| 1988 | 2.08578 |
| 1987 | 2.06394 |
| 1986 | 2.04189 |
| 1985 | 2.01984 |
| 1984 | 1.99727 |
| 1983 | 1.97228 |
| 1982 | 1.94505 |
| 1981 | 1.91688 |
| 1980 | 1.88784 |
| 1979 | 1.85755 |
| 1978 | 1.82597 |
| 1977 | 1.79413 |
| 1976 | 1.76249 |
| 1975 | 1.73034 |
| 1974 | 1.69853 |
| 1973 | 1.66825 |
| 1972 | 1.63855 |
| 1971 | 1.60883 |
| 1970 | 1.57757 |
| 1969 | 1.54393 |
| 1968 | 1.50859 |
| 1967 | 1.47143 |
| 1966 | 1.43126 |
| 1965 | 1.38767 |
| 1964 | 1.34083 |
| 1963 | 1.29049 |
| 1962 | 1.23689 |
| 1961 | 1.18063 |
| 1960 | 1.12277 |