| Current (1) |
| Chairman | 2022 |
| Former (21) |
| Board of Directors | 1997 – 2000 |
| Chairman | 1987 – 1994 |
| Board of Directors | 1987 – 2002 |
| Board of Directors | 1987 – 1992 |
| Chairman | 1987 – 2001 |
| Board of Directors | 1987 – 1994 |
| Board of Directors | 2015 – 2018 |
| Board of Directors | 1987 – 1992 |
| Board of Directors | 2005 – 2008 |
| Board of Directors | 1997 – 2001 |
| Chairman | 2016 – 2022 |
| Board of Directors | 1987 – 1994 |
| Chairman | 2003 – 2016 |
| Board of Directors | 2001 – 2001 |
| Board of Directors | 2021 – 2022 |
| Chairman | 2001 – 2003 |
| Board of Directors | 2015 – 2019 |
| Board of Directors | 2009 – 2015 |
| Board of Directors | 1997 – 1998 |
| Board of Directors | 2003 – 2015 |
| Board of Directors | 1997 – 2001 |