| Current (2) |
| Chairman | 2018 |
| Board of Directors | 2018 |
| Former (23) |
| Chairman | 2000 – 2001 |
| Board of Directors | 2011 – 2014 |
| Board of Directors | 1990 – 1999 |
| Board of Directors | 1990 – 1997 |
| Board of Directors | 2013 – 2017 |
| Board of Directors | 1990 – 1994 |
| Board of Directors | 2001 – 2003 |
| Board of Directors | 1997 – 1999 |
| Board of Directors | 1990 – 1994 |
| Board of Directors | 2005 – 2013 |
| Board of Directors | 1990 – 1994 |
| Chairman | 2018 – 2018 |
| Board of Directors | 1997 – 1999 |
| Board of Directors | 1994 – 1997 |
| Board of Directors | 2008 – 2011 |
| Board of Directors | 2002 – 2004 |
| Board of Directors | 2004 – 2005 |
| Chairman | 2001 – 2005 |
| Board of Directors | 1990 – 1994 |
| Chairman | 2005 – 2018 |
| Board of Directors | 2005 – 2010 |
| Board of Directors | 1990 – 1991 |
| Board of Directors | 2006 – 2008 |