| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | 19.6639 |
| 2021 | 19.7237 |
| 2020 | 19.7633 |
| 2019 | 19.7867 |
| 2018 | 19.8119 |
| 2017 | 19.8386 |
| 2016 | 19.8813 |
| 2015 | 19.9618 |
| 2014 | 20.0596 |
| 2013 | 20.1504 |
| 2012 | 20.2438 |
| 2011 | 20.324 |
| 2010 | 20.3747 |
| 2009 | 20.4176 |
| 2008 | 20.4542 |
| 2007 | 20.4838 |
| 2006 | 20.5069 |
| 2005 | 20.5207 |
| 2004 | 20.5221 |
| 2003 | 20.5187 |
| 2002 | 20.5134 |
| 2001 | 20.5006 |
| 2000 | 20.4697 |
| 1999 | 20.4017 |
| 1998 | 20.3011 |
| 1997 | 20.1802 |
| 1996 | 20.0535 |
| 1995 | 19.9552 |
| 1994 | 19.8981 |
| 1993 | 19.8747 |
| 1992 | 19.8909 |
| 1991 | 19.9414 |
| 1990 | 20.022 |
| 1989 | 20.1514 |
| 1988 | 20.3114 |
| 1987 | 20.4719 |
| 1986 | 20.6433 |
| 1985 | 20.8003 |
| 1984 | 20.8995 |
| 1983 | 20.9524 |
| 1982 | 20.9521 |
| 1981 | 20.889 |
| 1980 | 20.7951 |
| 1979 | 20.7023 |
| 1978 | 20.6305 |
| 1977 | 20.5993 |
| 1976 | 20.6116 |
| 1975 | 20.6544 |
| 1974 | 20.7266 |
| 1973 | 20.8284 |
| 1972 | 20.9615 |
| 1971 | 21.1213 |
| 1970 | 21.2918 |
| 1969 | 21.4673 |
| 1968 | 21.6439 |
| 1967 | 21.8045 |
| 1966 | 21.9535 |
| 1965 | 22.1056 |
| 1964 | 22.2511 |
| 1963 | 22.3826 |
| 1962 | 22.5066 |
| 1961 | 22.6259 |
| 1960 | 22.742 |