| Current (3) |
| Chairman | 2024 |
| Board of Directors | 2023 |
| Board of Directors | 2022 |
| Former (14) |
| Board of Directors | 1987 – 1992 |
| Board of Directors | 2015 – 2015 |
| Board of Directors | 1987 – 1987 |
| Board of Directors | 1987 – 1995 |
| Chairman | 2004 – 2008 |
| Board of Directors | 2000 – 2004 |
| Board of Directors | 2004 – 2015 |
| Board of Directors | 2015 – 2021 |
| Chairman | 1987 – 1992 |
| Board of Directors | 2021 – 2022 |
| Chairman | 2008 – 2024 |
| Chairman | 1987 – 2000 |
| Chairman | 1987 – 1987 |
| Chairman | 2000 – 2004 |