| Former (16) |
| Management | 2004 – 2004 |
| Management | 2004 – 2007 |
| Audit | 2004 – 2005 |
| Unofficial title | 1986 – 1993 |
| Unofficial title | 1986 – 2001 |
| Audit | 2005 – 2008 |
| Management | 1986 – 2004 |
| Unofficial title | 1986 – 1991 |
| Audit | 1986 – 2004 |
| Management | 2004 – 2009 |
| Unofficial title | 1986 – 2006 |
| Unofficial title | 2006 – 2008 |
| Unofficial title | 1986 – 1999 |
| Chief Executive Officer | 2008 – 2012 |
| Unofficial title | 1986 – 1995 |
| Unofficial title | 2001 – 2008 |