| 年份 | 博茨瓦纳 |
|---|---|
| 2023 | - |
| 2022 | 14.5641 |
| 2021 | 8.3499 |
| 2020 | 4.37899 |
| 2019 | 0.507585 |
| 2018 | 0.057197 |
| 2017 | -2.64992 |
| 2016 | 11.9049 |
| 2015 | 3.73032 |
| 2014 | 9.604 |
| 2013 | 1.53212 |
| 2012 | 3.01184 |
| 2011 | 12.6533 |
| 2010 | 7.68306 |
| 2009 | 15.1089 |
| 2008 | 9.37273 |
| 2007 | 6.0292 |
| 2006 | 5.1544 |
| 2005 | 15.4717 |
| 2004 | 10.0788 |
| 2003 | 3.25908 |
| 2002 | 1.18737 |
| 2001 | 8.31283 |
| 2000 | 14.171 |
| 1999 | 14.2352 |
| 1998 | 9.96727 |
| 1997 | 4.99061 |
| 1996 | 16.1122 |
| 1995 | 7.15529 |
| 1994 | 9.4638 |
| 1993 | 13.0647 |
| 1992 | 6.63928 |
| 1991 | 5.17771 |
| 1990 | 6.30002 |
| 1989 | 13.6488 |
| 1988 | 22.6971 |
| 1987 | 12.6941 |
| 1986 | 14.0612 |
| 1985 | 22.8937 |
| 1984 | 15.427 |
| 1983 | 8.74549 |
| 1982 | 3.69542 |
| 1981 | -0.0883228 |
| 1980 | 10.1903 |
| 1979 | 21.8564 |
| 1978 | 12.4668 |
| 1977 | 4.93738 |
| 1976 | 11.3155 |
| 1975 | 16.4673 |
| 1974 | 12.7969 |
| 1973 | 9.90661 |
| 1972 | 10.7754 |
| 1971 | 4.66418 |
| 1970 | 5.97859 |
| 1969 | 1.58436 |
| 1968 | 2.16615 |
| 1967 | 7.58155 |
| 1966 | 5.78874 |
| 1965 | 3.84628 |
| 1964 | 2.5475 |
| 1963 | 1.17683 |
| 1962 | 1.36074 |
| 1961 | 1.93395 |
| 1960 | - |