| Current (2) |
| Board of Directors | 2017 |
| Board of Directors | 2021 |
| Former (21) |
| Board of Directors | 2001 – 2003 |
| Board of Directors | 2001 – 2005 |
| Chairman | 2011 – 2012 |
| Chairman | 2013 – 2020 |
| Board of Directors | 1972 – 1992 |
| Chairman | 2007 – 2008 |
| Board of Directors | 1972 – 1989 |
| Chairman | 2021 – 2024 |
| Chairman | 2005 – 2007 |
| Board of Directors | 1996 – 1999 |
| Board of Directors | 1999 – 2000 |
| Board of Directors | 1972 – 1996 |
| Board of Directors | 2008 – 2011 |
| Deputy Chairman | 1972 – 1989 |
| Chairman | 1972 – 1993 |
| Chairman | 1999 – 2005 |
| Board of Directors | 2000 – 2001 |
| Board of Directors | 2011 – 2017 |
| Board of Directors | 1972 – 1989 |
| Board of Directors | 2010 – 2011 |
| Board of Directors | 1972 – 1992 |