| Former (16) |
| Unofficial title | 2014 – 2019 |
| Unofficial title | 2019 – 2020 |
| Unofficial title | 1987 – 2004 |
| Founder | 1987 – 2020 |
| Management | 2006 – 2007 |
| Unofficial title | 1987 – 2004 |
| Management | 1987 – 1998 |
| Management | 1987 – 1988 |
| Unofficial title | 1987 – 2003 |
| Management | 1999 – 2000 |
| Chief Executive Officer | 2002 – 2004 |
| Management | 2007 – 2014 |
| Management | 1987 – 1995 |
| Management | 2004 – 2006 |
| Management | 1998 – 2002 |
| Unofficial title | 2004 – 2004 |