| Current (2) |
| Deputy Chairman | 2018 |
| Chairman | 2016 |
| Former (29) |
| Board of Directors | 1976 – 2005 |
| Chairman | 2009 – 2014 |
| Chairman | 2014 – 2015 |
| Board of Directors | 2011 – 2012 |
| Deputy Chairman | 2009 – 2014 |
| Board of Directors | 1976 – 1994 |
| Board of Directors | 1976 – 1992 |
| Deputy Chairman | 2014 – 2018 |
| Board of Directors | 1976 – 2002 |
| Chairman | 2015 – 2016 |
| Board of Directors | 1976 – 1994 |
| Board of Directors | 2009 – 2010 |
| Board of Directors | 2002 – 2018 |
| Board of Directors | 2002 – 2006 |
| Board of Directors | 2010 – 2014 |
| Board of Directors | 2009 – 2010 |
| Board of Directors | 1976 – 1992 |
| Board of Directors | 1976 – 2003 |
| Chairman | 1976 – 1989 |
| Board of Directors | 2006 – 2010 |
| Board of Directors | 2014 – 2018 |
| Deputy Chairman | 1976 – 1993 |
| Board of Directors | 2010 – 2014 |
| Board of Directors | 1976 – 2002 |
| Board of Directors | 2005 – 2009 |
| Board of Directors | 2009 – 2010 |
| Board of Directors | 2010 – 2010 |
| Board of Directors | 2003 – 2009 |
| Chairman | 2001 – 2009 |
