| Current (2) |
| Board of Directors | 2019 |
| Chairman | 2019 |
| Former (16) |
| Board of Directors | 2008 – 2013 |
| Chairman | 2009 – 2013 |
| Chairman | 2013 – 2015 |
| Board of Directors | 2017 – 2019 |
| Board of Directors | 1999 – 2000 |
| Board of Directors | 2000 – 2004 |
| Board of Directors | 1999 – 2000 |
| Board of Directors | 2002 – 2008 |
| Board of Directors | 2013 – 2017 |
| Board of Directors | 1999 – 2006 |
| Chairman | 2015 – 2017 |
| Board of Directors | 2004 – 2008 |
| Chairman | 2017 – 2019 |
| Chairman | 2008 – 2009 |
| Board of Directors | 1986 – 1990 |
| Board of Directors | 1986 – 1999 |