| Former (18) |
| Chairman | 1997 – 2017 |
| Board of Directors | 1981 – 1997 |
| Board of Directors | 1997 – 2001 |
| Board of Directors | 1981 – 1997 |
| Board of Directors | 1997 – 2010 |
| Board of Directors | 1981 – 1996 |
| Board of Directors | 2016 – 2018 |
| Board of Directors | 1981 – 1989 |
| Chairman | 2017 – 2022 |
| Board of Directors | 2010 – 2015 |
| Board of Directors | 2013 – 2014 |
| Board of Directors | 1981 – 1996 |
| Board of Directors | 1981 – 1996 |
| Board of Directors | 1981 – 1988 |
| Board of Directors | 2004 – 2013 |
| Board of Directors | 2001 – 2004 |
| Board of Directors | 2018 – 2020 |
| Board of Directors | 2018 – 2022 |