| Former (16) |
| Management | 2006 – 2011 |
| Audit | 1995 – 1996 |
| Management | 1976 – 1996 |
| Management | 1996 – 1998 |
| Unofficial title | 2002 – 2005 |
| Management | 2002 – 2004 |
| Chief Executive Officer | 1998 – 2002 |
| Management | 1996 – 1998 |
| Audit | 1976 – 1995 |
| Management | 2006 – 2006 |
| Management | 2001 – 2002 |
| Unofficial title | 1998 – 2002 |
| Unofficial title | 1998 – 2002 |
| Chief Executive Officer | 2004 – 2005 |
| Management | 2006 – 2006 |
| Management | 2006 – 2006 |