| Current (2) |
| Chairman | 2019 |
| Board of Directors | 2017 |
| Former (27) |
| Board of Directors | 1987 – 1994 |
| Board of Directors | 1987 – 1988 |
| Chairman | 2012 – 2014 |
| Chairman | 1987 – 1997 |
| Board of Directors | 1987 – 1994 |
| Board of Directors | 1987 – 1992 |
| Board of Directors | 1987 – 2001 |
| Chairman | 2014 – 2019 |
| Chairman | 2002 – 2003 |
| Board of Directors | 1987 – 1996 |
| Board of Directors | 1987 – 1996 |
| Board of Directors | 1998 – 2012 |
| Board of Directors | 1987 – 1994 |
| Board of Directors | 2001 – 2002 |
| Board of Directors | 1987 – 1994 |
| Board of Directors | 1998 – 2001 |
| Board of Directors | 1987 – 1992 |
| Board of Directors | 1987 – 1994 |
| Board of Directors | 2001 – 2002 |
| Board of Directors | 2003 – 2007 |
| Board of Directors | 2001 – 2002 |
| Chairman | 1987 – 1988 |
| Board of Directors | 1987 – 2002 |
| Board of Directors | 2012 – 2017 |
| Board of Directors | 1996 – 1998 |
| Chairman | 2003 – 2012 |
| Board of Directors | 1987 – 1998 |
