| Current (2) |
| Chairman | 2019 |
| Board of Directors | 2019 |
| Former (12) |
| Chairman | 2007 – 2012 |
| Board of Directors | 2005 – 2008 |
| Board of Directors | 2008 – 2016 |
| Board of Directors | 2002 – 2004 |
| Board of Directors | 2004 – 2005 |
| Board of Directors | 2007 – 2008 |
| Board of Directors | 2012 – 2016 |
| Chairman | 1991 – 2007 |
| Board of Directors | 2000 – 2004 |
| Board of Directors | 2012 – 2018 |
| Board of Directors | 1991 – 1993 |
| Board of Directors | 2007 – 2011 |