| Former (20) |
| Board of Directors | 1996 – 1998 |
| Board of Directors | 1958 – 1987 |
| Board of Directors | 1998 – 2006 |
| Board of Directors | 1958 – 1993 |
| Board of Directors | 1958 – 1992 |
| Chairman | 1958 – 1990 |
| Chairman | 2012 – 2014 |
| Chairman | 2014 – 2015 |
| Board of Directors | 2006 – 2009 |
| Board of Directors | 2014 – 2015 |
| Board of Directors | 2001 – 2003 |
| Board of Directors | 2000 – 2009 |
| Board of Directors | 2011 – 2012 |
| Chairman | 1958 – 1992 |
| Board of Directors | 1998 – 2000 |
| Board of Directors | 2003 – 2011 |
| Chairman | 2009 – 2012 |
| Board of Directors | 2009 – 2012 |
| Board of Directors | 1958 – 1987 |
| Board of Directors | 1958 – 1998 |