| Current (2) |
| Board of Directors | 2020 |
| Chairman | 2020 |
| Former (14) |
| Board of Directors | 1946 – 1990 |
| Chairman | 2007 – 2009 |
| Chairman | 1946 – 2003 |
| Board of Directors | 1946 – 2003 |
| Chairman | 2004 – 2007 |
| Board of Directors | 1946 – 1990 |
| Chairman | 2009 – 2020 |
| Board of Directors | 1946 – 1988 |
| Board of Directors | 1996 – 2003 |
| Board of Directors | 1946 – 1991 |
| Board of Directors | 1992 – 1995 |
| Board of Directors | 1946 – 1992 |
| Chairman | 2003 – 2004 |
| Board of Directors | 1946 – 1990 |