| Former (13) |
| Board of Directors | 2011 – 2015 |
| Board of Directors | 1988 – 2002 |
| Board of Directors | 2015 – 2018 |
| Board of Directors | 1988 – 1998 |
| Board of Directors | 1988 – 1998 |
| Deputy Chairman | 1988 – 2000 |
| Deputy Chairman | 1998 – 2007 |
| Deputy Chairman | 2007 – 2010 |
| Deputy Chairman | 1988 – 1991 |
| Chairman | 1998 – 2010 |
| Chairman | 1988 – 1998 |
| Board of Directors | 1988 – 1992 |
| Board of Directors | 2010 – 2012 |