| Current (2) |
| Board of Directors | 2019 |
| Chairman | 2020 |
| Former (24) |
| Chairman | 2003 – 2004 |
| Chairman | 2011 – 2013 |
| Chairman | 2000 – 2003 |
| Board of Directors | 2004 – 2011 |
| Chairman | 2009 – 2011 |
| Chairman | 2019 – 2020 |
| Board of Directors | 1997 – 2000 |
| Board of Directors | 2002 – 2003 |
| Board of Directors | 2011 – 2013 |
| Board of Directors | 2008 – 2011 |
| Chairman | 2016 – 2017 |
| Board of Directors | 2000 – 2004 |
| Chairman | 2017 – 2019 |
| Chairman | 2017 – 2017 |
| Board of Directors | 2004 – 2004 |
| Board of Directors | 2004 – 2008 |
| Chairman | 1995 – 2000 |
| Chairman | 2013 – 2015 |
| Board of Directors | 1995 – 1997 |
| Chairman | 2015 – 2016 |
| Board of Directors | 2015 – 2016 |
| Board of Directors | 1995 – 2000 |
| Board of Directors | 2000 – 2002 |
| Board of Directors | 2016 – 2017 |