| Current (3) |
| Board of Directors | 2017 |
| Board of Directors | 2002 |
| Board of Directors | 2022 |
| Former (12) |
| Chairman | 2002 – 2022 |
| Board of Directors | 1978 – 2001 |
| Board of Directors | 2001 – 2004 |
| Board of Directors | 1978 – 1992 |
| Board of Directors | 2002 – 2013 |
| Board of Directors | 1978 – 1991 |
| Board of Directors | 2013 – 2022 |
| Board of Directors | 1978 – 2002 |
| Board of Directors | 1978 – 2000 |
| Chairman | 1978 – 2002 |
| Board of Directors | 2004 – 2013 |
| Board of Directors | 1978 – 1990 |