| Current (3) |
| Chairman | 2026 |
| Board of Directors | 2016 |
| Board of Directors | 2020 |
| Former (20) |
| Board of Directors | 2002 – 2006 |
| Chairman | 2001 – 2009 |
| Board of Directors | 1959 – 2002 |
| Board of Directors | 1999 – 2001 |
| Chairman | 1959 – 1994 |
| Board of Directors | 2005 – 2009 |
| Chairman | 1959 – 1996 |
| Board of Directors | 2001 – 2009 |
| Board of Directors | 1959 – 1993 |
| Chairman | 2020 – 2026 |
| Board of Directors | 2002 – 2005 |
| Board of Directors | 1996 – 2002 |
| Chairman | 2009 – 2015 |
| Board of Directors | 1959 – 1999 |
| Board of Directors | 2007 – 2016 |
| Board of Directors | 2006 – 2007 |
| Chairman | 2015 – 2020 |
| Board of Directors | 1959 – 1996 |
| Board of Directors | 1959 – 1989 |
| Board of Directors | 1996 – 2003 |