| Current (2) |
| Chairman | 2020 |
| Board of Directors | 2020 |
| Former (27) |
| Board of Directors | 1986 – 1992 |
| Board of Directors | 1986 – 1994 |
| Board of Directors | 1986 – 1999 |
| Board of Directors | 1996 – 1999 |
| Chairman | 1986 – 1991 |
| Board of Directors | 1986 – 1991 |
| Chairman | 2011 – 2013 |
| Board of Directors | 1986 – 1994 |
| Chairman | 2003 – 2008 |
| Chairman | 2008 – 2011 |
| Board of Directors | 2016 – 2020 |
| Board of Directors | 2011 – 2012 |
| Board of Directors | 1995 – 1997 |
| Board of Directors | 1986 – 1997 |
| Chairman | 1986 – 1988 |
| Board of Directors | 2013 – 2016 |
| Board of Directors | 2005 – 2010 |
| Board of Directors | 1986 – 1995 |
| Board of Directors | 1986 – 1992 |
| Board of Directors | 1986 – 1990 |
| Board of Directors | 1986 – 1988 |
| Board of Directors | 2012 – 2016 |
| Board of Directors | 1986 – 1990 |
| Board of Directors | 1986 – 1988 |
| Chairman | 1986 – 1998 |
| Chairman | 1998 – 1999 |
| Board of Directors | 1986 – 1993 |