| Current (2) |
| Board of Directors | 2020 |
| Chairman | 2019 |
| Former (16) |
| Board of Directors | 1972 – 1993 |
| Board of Directors | 1997 – 1999 |
| Board of Directors | 2017 – 2020 |
| Board of Directors | 1997 – 1999 |
| Deputy Chairman | 1999 – 2003 |
| Chairman | 2018 – 2019 |
| Board of Directors | 1972 – 1999 |
| Board of Directors | 1972 – 1988 |
| Board of Directors | 1972 – 1990 |
| Board of Directors | 2008 – 2014 |
| Board of Directors | 1997 – 1999 |
| Chairman | 1999 – 2005 |
| Board of Directors | 2019 – 2020 |
| Chairman | 2008 – 2015 |
| Deputy Chairman | 2003 – 2005 |
| Deputy Chairman | 2020 – 2020 |