| 年份 | 博茨瓦纳 |
|---|---|
| 2023 | - |
| 2022 | 3.2651 |
| 2021 | 3.21884 |
| 2020 | 3.16955 |
| 2019 | 3.11342 |
| 2018 | 3.05682 |
| 2017 | 2.99832 |
| 2016 | 2.93593 |
| 2015 | 2.87106 |
| 2014 | 2.80543 |
| 2013 | 2.73983 |
| 2012 | 2.67477 |
| 2011 | 2.61036 |
| 2010 | 2.54518 |
| 2009 | 2.47853 |
| 2008 | 2.39107 |
| 2007 | 2.28662 |
| 2006 | 2.19152 |
| 2005 | 2.10555 |
| 2004 | 2.02869 |
| 2003 | 1.99125 |
| 2002 | 1.99243 |
| 2001 | 2.00561 |
| 2000 | 2.02881 |
| 1999 | 2.05661 |
| 1998 | 2.08945 |
| 1997 | 2.1251 |
| 1996 | 2.1596 |
| 1995 | 2.19023 |
| 1994 | 2.21816 |
| 1993 | 2.24419 |
| 1992 | 2.26585 |
| 1991 | 2.27429 |
| 1990 | 2.26815 |
| 1989 | 2.25128 |
| 1988 | 2.21913 |
| 1987 | 2.18043 |
| 1986 | 2.15511 |
| 1985 | 2.15561 |
| 1984 | 2.18268 |
| 1983 | 2.24023 |
| 1982 | 2.31704 |
| 1981 | 2.38824 |
| 1980 | 2.43102 |
| 1979 | 2.43835 |
| 1978 | 2.41029 |
| 1977 | 2.34749 |
| 1976 | 2.27211 |
| 1975 | 2.20156 |
| 1974 | 2.13284 |
| 1973 | 2.0613 |
| 1972 | 2.0018 |
| 1971 | 1.96867 |
| 1970 | 1.9571 |
| 1969 | 1.96347 |
| 1968 | 1.99667 |
| 1967 | 2.0541 |
| 1966 | 2.12778 |
| 1965 | 2.21168 |
| 1964 | 2.31569 |
| 1963 | 2.44908 |
| 1962 | 2.59055 |
| 1961 | 2.70712 |
| 1960 | 2.78187 |