| Current (2) |
| Board of Directors | 2014 |
| Chairman | 2014 |
| Former (22) |
| Board of Directors | 1982 – 1994 |
| Board of Directors | 1997 – 2000 |
| Chairman | 1982 – 1994 |
| Chairman | 2001 – 2005 |
| Board of Directors | 2004 – 2005 |
| Board of Directors | 1982 – 1997 |
| Board of Directors | 1996 – 1998 |
| Chairman | 1982 – 2001 |
| Board of Directors | 1997 – 1999 |
| Board of Directors | 2005 – 2012 |
| Board of Directors | 1982 – 1999 |
| Chairman | 2009 – 2013 |
| Chairman | 2013 – 2014 |
| Board of Directors | 2013 – 2014 |
| Board of Directors | 2005 – 2006 |
| Chairman | 2006 – 2009 |
| Board of Directors | 2006 – 2013 |
| Board of Directors | 1982 – 2002 |
| Board of Directors | 2002 – 2004 |
| Board of Directors | 1999 – 2000 |
| Board of Directors | 1982 – 1994 |
| Chairman | 2005 – 2006 |