| 1973 | Members (21): Australia, Austria, Belgium, Bulgaria, Canada, Czechoslovakia, Denmark, Finland, France, Germany (BRD and DDR), Hungary, Israel, Japan, New Zealand, Norway, Poland, Sweden, Switzerland, UK, USA |
| 1973 | Members (21): Australia, Austria, Belgium, Bulgaria, Canada, Czechoslovakia, Denmark, Finland, France, Germany (BRD and DDR), Hungary, Israel, Japan, New Zealand, Norway, Poland, Sweden, Switzerland, UK, USA |