| Chairman | 2009 – 2012 |
| Board of Directors | 1961 – 1992 |
| Board of Directors | 1961 – 1991 |
| Chairman | 2001 – 2006 |
| Chairman | 2006 – 2009 |
| Board of Directors | 1961 – 2005 |
| Board of Directors | 1961 – 1992 |
| Board of Directors | 1999 – 2019 |
| Board of Directors | 1961 – 1994 |
| Chairman | 2017 – 2019 |
| Board of Directors | 1961 – 1996 |
| Board of Directors | 1961 – 1992 |
| Board of Directors | 2006 – 2013 |
| Board of Directors | 2013 – 2019 |
| Board of Directors | 1961 – 1987 |
| Board of Directors | 1996 – 2006 |
| Board of Directors | 1961 – 1994 |
| Board of Directors | 1961 – 1991 |
| Chairman | 2012 – 2017 |
| Board of Directors | 1961 – 1995 |
| Board of Directors | 1961 – 2001 |
| Board of Directors | 1961 – 1990 |
| Board of Directors | 1961 – 1997 |
| Board of Directors | 1961 – 1993 |