| Current (3) |
| Board of Directors | 2023 |
| Chairman | 2019 |
| Board of Directors | 2021 |
| Former (12) |
| Board of Directors | 1971 – 1994 |
| Board of Directors | 2017 – 2021 |
| Board of Directors | 2019 – 2023 |
| Board of Directors | 1971 – 2005 |
| Board of Directors | 1971 – 1994 |
| Board of Directors | 2005 – 2015 |
| Board of Directors | 2015 – 2017 |
| Board of Directors | 2005 – 2018 |
| Chairman | 2009 – 2019 |
| Board of Directors | 2018 – 2019 |
| Board of Directors | 1971 – 1994 |
| Chairman | 2005 – 2009 |