| 年份 | 博茨瓦纳 |
|---|---|
| 2023 | - |
| 2022 | 3.65404 |
| 2021 | 3.59248 |
| 2020 | 3.54836 |
| 2019 | 3.46735 |
| 2018 | 3.38836 |
| 2017 | 3.31737 |
| 2016 | 3.25514 |
| 2015 | 3.20388 |
| 2014 | 3.16248 |
| 2013 | 3.14487 |
| 2012 | 3.1483 |
| 2011 | 3.15231 |
| 2010 | 3.15667 |
| 2009 | 3.16494 |
| 2008 | 3.17869 |
| 2007 | 3.19661 |
| 2006 | 3.21599 |
| 2005 | 3.23274 |
| 2004 | 3.24391 |
| 2003 | 3.24926 |
| 2002 | 3.24979 |
| 2001 | 3.24968 |
| 2000 | 3.24959 |
| 1999 | 3.24544 |
| 1998 | 3.23431 |
| 1997 | 3.21783 |
| 1996 | 3.20095 |
| 1995 | 3.18702 |
| 1994 | 3.17699 |
| 1993 | 3.17211 |
| 1992 | 3.16574 |
| 1991 | 3.14465 |
| 1990 | 3.1064 |
| 1989 | 3.05699 |
| 1988 | 2.99717 |
| 1987 | 2.93114 |
| 1986 | 2.86984 |
| 1985 | 2.82123 |
| 1984 | 2.78469 |
| 1983 | 2.76143 |
| 1982 | 2.75359 |
| 1981 | 2.76607 |
| 1980 | 2.80328 |
| 1979 | 2.86184 |
| 1978 | 2.9431 |
| 1977 | 3.04498 |
| 1976 | 3.16254 |
| 1975 | 3.29249 |
| 1974 | 3.43501 |
| 1973 | 3.59082 |
| 1972 | 3.74895 |
| 1971 | 3.87113 |
| 1970 | 3.92077 |
| 1969 | 3.91376 |
| 1968 | 3.88008 |
| 1967 | 3.83421 |
| 1966 | 3.79652 |
| 1965 | 3.78038 |
| 1964 | 3.81673 |
| 1963 | 3.90599 |
| 1962 | 4.00855 |
| 1961 | 4.10629 |
| 1960 | 4.18532 |