| 年份 | 尼日尔 |
|---|---|
| 2023 | - |
| 2022 | - |
| 2021 | 33.7 |
| 2020 | 33.9 |
| 2019 | 33.9 |
| 2018 | 33.9 |
| 2017 | 33.9 |
| 2016 | 33.8 |
| 2015 | 33.8 |
| 2014 | 33.7 |
| 2013 | 33.7 |
| 2012 | 33.7 |
| 2011 | 33.9 |
| 2010 | 34.2 |
| 2009 | 34.6 |
| 2008 | 35.2 |
| 2007 | 36 |
| 2006 | 36.8 |
| 2005 | 37.7 |
| 2004 | 38.8 |
| 2003 | 40 |
| 2002 | 41.3 |
| 2001 | 42.7 |
| 2000 | 44.1 |
| 1999 | 45.5 |
| 1998 | 46.7 |
| 1997 | 47.8 |
| 1996 | 48.8 |
| 1995 | 49.8 |
| 1994 | 50.9 |
| 1993 | 52.1 |
| 1992 | 53.3 |
| 1991 | 54.2 |
| 1990 | 55.1 |
| 1989 | 55.9 |
| 1988 | 56.6 |
| 1987 | 57.1 |
| 1986 | 57.4 |
| 1985 | 57.5 |
| 1984 | 57.3 |
| 1983 | 57.1 |
| 1982 | 56.9 |
| 1981 | 56.8 |
| 1980 | 57.1 |
| 1979 | 57.7 |
| 1978 | 58.6 |
| 1977 | 59.6 |
| 1976 | 60.6 |
| 1975 | 61.3 |
| 1974 | 61.7 |
| 1973 | 61.7 |
| 1972 | 61.5 |
| 1971 | 61 |
| 1970 | 60.4 |
| 1969 | 59.9 |
| 1968 | - |
| 1967 | - |
| 1966 | - |
| 1965 | - |
| 1964 | - |
| 1963 | - |
| 1962 | - |
| 1961 | - |
| 1960 | - |