| Current (5) |
| Board of Directors | 2010 |
| Board of Directors | 2019 |
| Chairman | 2012 |
| Board of Directors | 2019 |
| Board of Directors | 2019 |
| Former (15) |
| Chairman | 2009 – 2010 |
| Board of Directors | 1954 – 1989 |
| Board of Directors | 1954 – 1988 |
| Chairman | 1954 – 1993 |
| Board of Directors | 2009 – 2010 |
| Board of Directors | 1954 – 1994 |
| Chairman | 1954 – 1994 |
| Board of Directors | 1954 – 1990 |
| Board of Directors | 1954 – 1993 |
| Chairman | 1954 – 1987 |
| Board of Directors | 1954 – 2009 |
| Board of Directors | 1954 – 2002 |
| Board of Directors | 1954 – 1994 |
| Chairman | 1954 – 1991 |
| Board of Directors | 1954 – 1987 |