| Former (16) |
| Unofficial title | 1985 – 1994 |
| Management | 2003 – 2003 |
| Chief Executive Officer | 2002 – 2003 |
| Unofficial title | 1985 – 1994 |
| Management | 1985 – 1995 |
| Management | 2007 – 2008 |
| Unofficial title | 2003 – 2004 |
| Unofficial title | 1985 – 2003 |
| Management | 1985 – 1991 |
| Unofficial title | 1985 – 1996 |
| Management | 2003 – 2007 |
| Chief Executive Officer | 1997 – 1997 |
| Management | 1995 – 1997 |
| Chief Executive Officer | 1997 – 2002 |
| Unofficial title | 2008 – 2012 |
| Unofficial title | 1998 – 2003 |