| Current (2) |
| Chairman | 2022 |
| Board of Directors | 2017 |
| Former (17) |
| Board of Directors | 1977 – 1998 |
| Chairman | 2003 – 2004 |
| Board of Directors | 2010 – 2014 |
| Board of Directors | 2009 – 2010 |
| Chairman | 1977 – 1989 |
| Chairman | 2004 – 2005 |
| Chairman | 2017 – 2022 |
| Board of Directors | 2014 – 2017 |
| Board of Directors | 1999 – 2001 |
| Board of Directors | 2005 – 2009 |
| Board of Directors | 2005 – 2009 |
| Board of Directors | 2005 – 2008 |
| Chairman | 2009 – 2014 |
| Board of Directors | 1977 – 1992 |
| Board of Directors | 2017 – 2017 |
| Chairman | 2005 – 2008 |
| Chairman | 2008 – 2009 |