| 年份 | 尼日利亚 |
|---|---|
| 2023 | - |
| 2022 | - |
| 2021 | 34.9 |
| 2020 | 35.5 |
| 2019 | 35.9 |
| 2018 | 36.4 |
| 2017 | 36.7 |
| 2016 | 37 |
| 2015 | 37.2 |
| 2014 | 37.4 |
| 2013 | 37.4 |
| 2012 | 37.6 |
| 2011 | 37.8 |
| 2010 | 38.1 |
| 2009 | 38.5 |
| 2008 | 38.9 |
| 2007 | 39.4 |
| 2006 | 40.1 |
| 2005 | 40.9 |
| 2004 | 41.9 |
| 2003 | 43 |
| 2002 | 44.2 |
| 2001 | 45.4 |
| 2000 | 46.4 |
| 1999 | 47.4 |
| 1998 | 48.2 |
| 1997 | 48.8 |
| 1996 | 49.3 |
| 1995 | 49.7 |
| 1994 | 49.9 |
| 1993 | 49.9 |
| 1992 | 49.9 |
| 1991 | 49.8 |
| 1990 | 49.8 |
| 1989 | 49.7 |
| 1988 | 49.6 |
| 1987 | 49.5 |
| 1986 | 49.6 |
| 1985 | 49.8 |
| 1984 | 50.2 |
| 1983 | 50.8 |
| 1982 | 51.5 |
| 1981 | 52.4 |
| 1980 | 53.4 |
| 1979 | 54.6 |
| 1978 | 55.8 |
| 1977 | 57 |
| 1976 | 58.3 |
| 1975 | 59.7 |
| 1974 | 61 |
| 1973 | 62.4 |
| 1972 | 63.7 |
| 1971 | 65.1 |
| 1970 | 66.4 |
| 1969 | 67.7 |
| 1968 | 68.8 |
| 1967 | 69.8 |
| 1966 | - |
| 1965 | - |
| 1964 | - |
| 1963 | - |
| 1962 | - |
| 1961 | - |
| 1960 | - |