| Current (2) |
| Chairman | 2014 |
| Board of Directors | 2022 |
| Former (32) |
| Board of Directors | 2005 – 2006 |
| Chairman | 2011 – 2012 |
| Board of Directors | 1961 – 1997 |
| Board of Directors | 2014 – 2018 |
| Board of Directors | 2020 – 2022 |
| Board of Directors | 2003 – 2006 |
| Board of Directors | 2006 – 2007 |
| Board of Directors | 2011 – 2014 |
| Board of Directors | 1999 – 2001 |
| Chairman | 2003 – 2011 |
| Board of Directors | 1961 – 1999 |
| Board of Directors | 1999 – 2005 |
| Board of Directors | 2018 – 2018 |
| Board of Directors | 1999 – 2003 |
| Board of Directors | 2006 – 2014 |
| Board of Directors | 2003 – 2018 |
| Board of Directors | 1961 – 1999 |
| Board of Directors | 1961 – 1994 |
| Board of Directors | 1961 – 2001 |
| Board of Directors | 1961 – 2006 |
| Board of Directors | 2014 – 2018 |
| Board of Directors | 1961 – 1996 |
| Board of Directors | 2012 – 2014 |
| Board of Directors | 2001 – 2012 |
| Chairman | 2001 – 2003 |
| Board of Directors | 1961 – 1991 |
| Board of Directors | 1995 – 2005 |
| Board of Directors | 1961 – 1999 |
| Board of Directors | 2007 – 2014 |
| Board of Directors | 1961 – 1991 |
| Board of Directors | 2005 – 2014 |
| Board of Directors | 2012 – 2014 |
