| 年份 | 尼日利亚 |
|---|---|
| 2023 | - |
| 2022 | 0.288791 |
| 2021 | 0.289504 |
| 2020 | 0.294324 |
| 2019 | 0.294917 |
| 2018 | 0.292012 |
| 2017 | 0.289117 |
| 2016 | 0.286343 |
| 2015 | 0.28372 |
| 2014 | 0.281277 |
| 2013 | 0.278936 |
| 2012 | 0.276759 |
| 2011 | 0.274694 |
| 2010 | 0.272828 |
| 2009 | 0.271183 |
| 2008 | 0.269758 |
| 2007 | 0.268561 |
| 2006 | 0.267326 |
| 2005 | 0.266096 |
| 2004 | 0.265145 |
| 2003 | 0.264411 |
| 2002 | 0.263834 |
| 2001 | 0.26319 |
| 2000 | 0.262359 |
| 1999 | 0.261782 |
| 1998 | 0.261699 |
| 1997 | 0.262268 |
| 1996 | 0.26352 |
| 1995 | 0.265177 |
| 1994 | 0.266944 |
| 1993 | 0.268637 |
| 1992 | 0.270423 |
| 1991 | 0.272053 |
| 1990 | 0.27308 |
| 1989 | 0.273636 |
| 1988 | 0.273943 |
| 1987 | 0.274276 |
| 1986 | 0.274844 |
| 1985 | 0.275659 |
| 1984 | 0.276596 |
| 1983 | 0.278057 |
| 1982 | 0.279881 |
| 1981 | 0.281183 |
| 1980 | 0.281463 |
| 1979 | 0.280304 |
| 1978 | 0.27714 |
| 1977 | 0.272075 |
| 1976 | 0.266057 |
| 1975 | 0.260146 |
| 1974 | 0.2544 |
| 1973 | 0.248351 |
| 1972 | 0.242298 |
| 1971 | 0.23643 |
| 1970 | 0.230798 |
| 1969 | 0.225604 |
| 1968 | 0.220926 |
| 1967 | 0.216921 |
| 1966 | 0.21276 |
| 1965 | 0.208261 |
| 1964 | 0.204264 |
| 1963 | 0.200434 |
| 1962 | 0.196491 |
| 1961 | 0.192648 |
| 1960 | 0.188967 |