| 年份 | 尼日利亚 |
|---|---|
| 2023 | - |
| 2022 | 8.84539 |
| 2021 | 8.75535 |
| 2020 | 8.68353 |
| 2019 | 8.6332 |
| 2018 | 8.60752 |
| 2017 | 8.58619 |
| 2016 | 8.55753 |
| 2015 | 8.53295 |
| 2014 | 8.51837 |
| 2013 | 8.51087 |
| 2012 | 8.51535 |
| 2011 | 8.5427 |
| 2010 | 8.59646 |
| 2009 | 8.67622 |
| 2008 | 8.78452 |
| 2007 | 8.9061 |
| 2006 | 9.01853 |
| 2005 | 9.11466 |
| 2004 | 9.18718 |
| 2003 | 9.233 |
| 2002 | 9.25247 |
| 2001 | 9.24391 |
| 2000 | 9.20727 |
| 1999 | 9.14054 |
| 1998 | 9.03706 |
| 1997 | 8.91405 |
| 1996 | 8.79299 |
| 1995 | 8.66989 |
| 1994 | 8.5462 |
| 1993 | 8.44006 |
| 1992 | 8.3556 |
| 1991 | 8.29078 |
| 1990 | 8.248 |
| 1989 | 8.22562 |
| 1988 | 8.21869 |
| 1987 | 8.22322 |
| 1986 | 8.23572 |
| 1985 | 8.25028 |
| 1984 | 8.26302 |
| 1983 | 8.2795 |
| 1982 | 8.29624 |
| 1981 | 8.30814 |
| 1980 | 8.3152 |
| 1979 | 8.32023 |
| 1978 | 8.33124 |
| 1977 | 8.33844 |
| 1976 | 8.34532 |
| 1975 | 8.35459 |
| 1974 | 8.31104 |
| 1973 | 8.25555 |
| 1972 | 8.27052 |
| 1971 | 8.32886 |
| 1970 | 8.40081 |
| 1969 | 8.53485 |
| 1968 | 8.68652 |
| 1967 | 8.75505 |
| 1966 | 8.77327 |
| 1965 | 8.77038 |
| 1964 | 8.76087 |
| 1963 | 8.7576 |
| 1962 | 8.76017 |
| 1961 | 8.7613 |
| 1960 | 8.75552 |