| Former (18) |
| Board of Directors | 1981 – 1989 |
| Board of Directors | 1999 – 2002 |
| Board of Directors | 2020 – 2021 |
| Chairman | 2018 – 2022 |
| Board of Directors | 1981 – 1992 |
| Board of Directors | 1981 – 1989 |
| Chairman | 2009 – 2017 |
| Board of Directors | 1981 – 1994 |
| Board of Directors | 1981 – 1989 |
| Board of Directors | 1981 – 1990 |
| Board of Directors | 1981 – 1996 |
| Board of Directors | 2002 – 2003 |
| Board of Directors | 2021 – 2022 |
| Board of Directors | 1996 – 1999 |
| Chairman | 1996 – 2009 |
| Board of Directors | 1981 – 1992 |
| Board of Directors | 1981 – 1989 |
| Board of Directors | 2003 – 2020 |