| Current (6) |
| Board of Directors | 2020 |
| Chairman | 2019 |
| Board of Directors | 2018 |
| Board of Directors | 2006 |
| Board of Directors | 2018 |
| Board of Directors | 2013 |
| Former (14) |
| Board of Directors | 2006 – 2020 |
| Board of Directors | 1996 – 1997 |
| Board of Directors | 1955 – 1990 |
| Board of Directors | 1955 – 1988 |
| Board of Directors | 1955 – 2018 |
| Chairman | 2001 – 2005 |
| Chairman | 2006 – 2019 |
| Board of Directors | 2006 – 2015 |
| Board of Directors | 2005 – 2006 |
| Board of Directors | 1955 – 2006 |
| Chairman | 1955 – 2001 |
| Chairman | 2005 – 2006 |
| Board of Directors | 1955 – 1989 |
| Board of Directors | 1999 – 2006 |