| Former (18) |
| Board of Directors | 1987 – 1994 |
| Chairman | 2008 – 2011 |
| Board of Directors | 2009 – 2013 |
| Chairman | 2004 – 2008 |
| Board of Directors | 2005 – 2008 |
| Board of Directors | 1987 – 1987 |
| Board of Directors | 1995 – 2004 |
| Chairman | 2003 – 2004 |
| Board of Directors | 2016 – 2019 |
| Board of Directors | 1998 – 2000 |
| Board of Directors | 1995 – 1996 |
| Chairman | 2011 – 2019 |
| Board of Directors | 2013 – 2019 |
| Board of Directors | 1987 – 1995 |
| Chairman | 1987 – 1987 |
| Board of Directors | 2008 – 2009 |
| Board of Directors | 1998 – 1998 |
| Board of Directors | 1987 – 1998 |