| Current (2) |
| Board of Directors | 2010 |
| Chairman | 2003 |
| Former (12) |
| Board of Directors | 1960 – 2001 |
| Board of Directors | 2003 – 2010 |
| Chairman | 1960 – 2003 |
| Board of Directors | 1960 – 1986 |
| Board of Directors | 2009 – 2010 |
| Board of Directors | 1960 – 2005 |
| Board of Directors | 1960 – 1991 |
| Board of Directors | 1960 – 1995 |
| Board of Directors | 1960 – 1994 |
| Board of Directors | 1960 – 2005 |
| Board of Directors | 2001 – 2010 |
| Board of Directors | 1960 – 1994 |