| Current (2) |
| Chairman | 2023 |
| Board of Directors | 2004 |
| Former (15) |
| Chairman | 1997 – 2018 |
| Board of Directors | 1981 – 1993 |
| Chairman | 1996 – 1997 |
| Board of Directors | 1981 – 2003 |
| Board of Directors | 1996 – 1997 |
| Chairman | 1981 – 1996 |
| Board of Directors | 1997 – 1997 |
| Board of Directors | 1981 – 1991 |
| Board of Directors | 1997 – 2020 |
| Board of Directors | 1981 – 1996 |
| Board of Directors | 1996 – 1997 |
| Board of Directors | 1981 – 1996 |
| Chairman | 1996 – 1997 |
| Board of Directors | 1981 – 1995 |
| Chairman | 2021 – 2023 |