17th (1968) – ISRAEL (Jerusalem)
16th (1965) – POLAND (Warsaw)
15th (1962) – USA (Madison, Wisconsin)
14th (1959) – AUSTRIA (Vienna)
13th (1956) – FINLAND (Helsinki)
12th (1953) – ENGLAND (Cambridge)
11th (1950) – BELGIUM (Ghent)
10th (1948) – SWITZERLAND (Zürich)
9th (1939) – SWEDEN (Stockholm)
8th (1937) – FRANCE (Paris)