| Current (4) |
| Chairman | 2018 |
| Board of Directors | 2019 |
| Board of Directors | 2014 |
| Board of Directors | 2011 |
| Former (19) |
| Chairman | 2007 – 2018 |
| Board of Directors | 2003 – 2004 |
| Board of Directors | 2004 – 2011 |
| Board of Directors | 2002 – 2003 |
| Board of Directors | 1999 – 1999 |
| Board of Directors | 2014 – 2015 |
| Board of Directors | 2007 – 2011 |
| Board of Directors | 2003 – 2004 |
| Board of Directors | 2001 – 2003 |
| Chairman | 1975 – 2002 |
| Board of Directors | 1999 – 2009 |
| Board of Directors | 2015 – 2019 |
| Board of Directors | 2002 – 2009 |
| Board of Directors | 1999 – 2001 |
| Board of Directors | 1999 – 1999 |
| Board of Directors | 2011 – 2014 |
| Board of Directors | 2009 – 2014 |
| Board of Directors | 2003 – 2004 |
| Chairman | 2002 – 2007 |
