| Current (2) |
| Chairman | 2026 |
| Board of Directors | 2026 |
| Former (18) |
| Chairman | 1998 – 2000 |
| Chairman | 2016 – 2022 |
| Board of Directors | 2000 – 2002 |
| Chairman | 2022 – 2026 |
| Board of Directors | 1997 – 2000 |
| Board of Directors | 1968 – 1992 |
| Chairman | 1968 – 1990 |
| Chairman | 1968 – 1996 |
| Chairman | 2003 – 2011 |
| Chairman | 2000 – 2001 |
| Board of Directors | 1968 – 1997 |
| Chairman | 2011 – 2016 |
| Board of Directors | 2016 – 2026 |
| Chairman | 1996 – 1998 |
| Board of Directors | 2006 – 2008 |
| Chairman | 2001 – 2003 |
| Board of Directors | 2003 – 2005 |
| Board of Directors | 1968 – 1994 |