This is their official website:
http://www . IMO 20 1 1 . nl/
The 49th Madrid, Spain (July 22nd, 2008 10-22),10/countries participated.
50th Bremen, Germany (2009)
No.51Astana, Kazakhstan (20 10)
The 52nd Amsterdam, Netherlands (20 1 1)
The 53rd Argentina (20 12)
The above are the venues for competitions in the last five years;
The champion of the past five years
2005: People's Republic of China (PRC)
2006: People's Republic of China (PRC)
2007: Russia
2008: People's Republic of China (PRC)
2009: People's Republic of China (PRC)
You should be good at math, right? Hehe, come on!