| 年份 | 博茨瓦纳 |
|---|---|
| 2023 | - |
| 2022 | - |
| 2021 | 0.100447 |
| 2020 | 0.102105 |
| 2019 | 0.104012 |
| 2018 | 0.105898 |
| 2017 | 0.108084 |
| 2016 | 0.110355 |
| 2015 | 0.112616 |
| 2014 | 0.177847 |
| 2013 | 0.126281 |
| 2012 | 0.131009 |
| 2011 | 0.151825 |
| 2010 | 0.123825 |
| 2009 | 0.154222 |
| 2008 | 0.138991 |
| 2007 | 0.0925278 |
| 2006 | 0.104215 |
| 2005 | 0.112795 |
| 2004 | 0.121565 |
| 2003 | 0.10674 |
| 2002 | 0.13648 |
| 2001 | 0.113512 |
| 2000 | 0.202665 |
| 1999 | 0.141881 |
| 1998 | 0.138914 |
| 1997 | 0.185259 |
| 1996 | 0.218055 |
| 1995 | 0.223499 |
| 1994 | 0.262713 |
| 1993 | 0.239355 |
| 1992 | 0.17597 |
| 1991 | 0.217299 |
| 1990 | 0.313088 |
| 1989 | 0.318053 |
| 1988 | 0.324276 |
| 1987 | 0.335147 |
| 1986 | 0.345131 |
| 1985 | 0.357424 |
| 1984 | 0.36846 |
| 1983 | 0.381817 |
| 1982 | 0.395891 |
| 1981 | 0.410075 |
| 1980 | 0.429373 |
| 1979 | 0.451035 |
| 1978 | 0.472101 |
| 1977 | 0.496922 |
| 1976 | 0.523209 |
| 1975 | 0.550877 |
| 1974 | 0.579841 |
| 1973 | 0.610122 |
| 1972 | 0.639961 |
| 1971 | 0.662099 |
| 1970 | 0.675397 |
| 1969 | 0.681736 |
| 1968 | 0.686513 |
| 1967 | 0.691177 |
| 1966 | 0.695828 |
| 1965 | 0.700556 |
| 1964 | 0.709618 |
| 1963 | 0.726722 |
| 1962 | 0.743809 |
| 1961 | 0.760865 |
| 1960 | - |