| Current (2) |
| Board of Directors | 2018 |
| Board of Directors | 2026 |
| Former (13) |
| Board of Directors | 2013 – 2017 |
| Board of Directors | 2011 – 2013 |
| Board of Directors | 2013 – 2025 |
| Chairman | 2014 – 2019 |
| Board of Directors | 2004 – 2011 |
| Board of Directors | 2019 – 2025 |
| Chairman | 2001 – 2014 |
| Board of Directors | 2001 – 2004 |
| Chairman | 1974 – 1998 |
| Board of Directors | 2025 – 2026 |
| Chairman | 1974 – 2001 |
| Board of Directors | 2011 – 2013 |
| Board of Directors | 1998 – 2001 |