| Current (2) |
| Chairman | 2014 |
| Board of Directors | 2017 |
| Former (21) |
| Board of Directors | 2012 – 2014 |
| Board of Directors | 2005 – 2008 |
| Chairman | 1991 – 2001 |
| Board of Directors | 2008 – 2009 |
| Board of Directors | 1991 – 1999 |
| Board of Directors | 2006 – 2006 |
| Board of Directors | 1999 – 2001 |
| Board of Directors | 2009 – 2012 |
| Chairman | 2012 – 2012 |
| Board of Directors | 1991 – 1997 |
| Board of Directors | 2007 – 2008 |
| Chairman | 2002 – 2004 |
| Board of Directors | 2002 – 2006 |
| Chairman | 2012 – 2014 |
| Board of Directors | 2014 – 2017 |
| Board of Directors | 2008 – 2012 |
| Board of Directors | 2001 – 2001 |
| Board of Directors | 2006 – 2007 |
| Chairman | 2001 – 2002 |
| Board of Directors | 1991 – 2001 |
| Board of Directors | 2004 – 2004 |