The international congresses have been held as follows:

• Tokyo 2022: attendance
• Buenos Aires 2017: attendance 3038.
• Granada 2013: attendance 3896.
• Bangkok 2009: attendance 4,070 from 106 countries.
• Durban 2005: attendance 2100 from 92 countries.
• Vienna 2001: attendance 3550 from 113 countries.
• Montreal 1997: attendance 3250 from 92 countries.
• Adelaide 1993: attendance 2600 from 91 countries.
• Seoul 1989: attendance 3500 from 104 countries.
• Brighton 1985: attendance 2300 from 92 countries.
• San Diego 1981: attendance 2500 from 83 countries, 1011 papers.
• Rio de Janeiro 1978: attendance 3500 from 92 countries, 1200 papers.
• Kyoto 1975: attendance 2300 from 55 countries, 900 papers.
• Mexico City 1972: attendance 2000 from 66 countries, 834 papers.
• Prague 1969: attendance 1800 from 62 countries, 896 papers.
• Hamburg 1966: attendance 2100 from 81 countries, 800 papers.
• Edinburgh 1963: attendance 1500 from 63 countries, 225 papers.
• Washington 1960: attendance 2000 from 65 countries, 413 papers.
• Paris 1957: attendance 1000 from 22 countries, 367 papers.
• Amsterdam 1954: attendance 360 from 32 countries.
• Basle 1952: attendance 150 from 18 countries.
• London 1946: attendance 22 from 17 countries.