I  1932  Amsterdam
    II  1935  London
   III  1938  Gent
    IV  1961  Helsinki
     V  1964  Münster
    VI  1967  Prague
   VII  1971  Montreal
  VIII  1975  Leeds
    IX  1979  Copenhagen
     X  1983  Utrecht
    XI  1987  Tallinn
   XII  1991  Aix-en-Provence
  XIII  1995  Stockholm
   XIV  1999  San Francisco 
    XV  2003  Barcelona 
   XVI  2007  Saarbrücken 
  XVII  2011  Hong Kong