| Country or Area | Year(s) | Value | |
|---|
| United Republic of Tanzania | 2012 | 7.0 |
| United Republic of Tanzania | 2011 | 7.4 |
| United Republic of Tanzania | 2010 | 7.2 |
| United Republic of Tanzania | 2009 | 5.6 |
| United Republic of Tanzania | 2008 | 5.4 |
| United Republic of Tanzania | 2007 | 5.7 |
| United Republic of Tanzania | 2006 | 6.5 |
| United Republic of Tanzania | 2005 | 4.0 |
| United Republic of Tanzania | 2004 | 3.4 |
| United Republic of Tanzania | 2003 | 3.8 |
| United Republic of Tanzania | 2002 | 3.4 |
| United Republic of Tanzania | 2001 | 3.5 |
| United Republic of Tanzania | 2000 | 3.4 |
| United Republic of Tanzania | 1999 | 3.5 |
| United Republic of Tanzania | 1998 | 3.4 |
| United Republic of Tanzania | 1997 | 3.6 |
| United Republic of Tanzania | 1996 | 3.6 |
| United Republic of Tanzania | 1995 | 3.9 |
