| 1952 |
| 1953 |
| 1959 - 1963 |
| 1963 - 1969 |
| 1969 - 1971 |
| 1971 - 1974 |
| 1974 - 1977 |
| 1977 |
| 1978 - 1979 |
| 1979 - 1988 |
| 1989 |
| 1989 |
| 1989 |
| 1990 - 1997 |
| 1993 |
| 1998 - 2018 |
© Stephan Weber