2008 Summer Olympics in Beijing expected approximately 10,500 athletes to take part in the 302 events on the program for the games. The United States has hosted four Summer Olympics Games, more than any other nation. The United Kingdom will have hosted three Summer Olympics Games when they return to the British capital in 2012, all of them have been (and will be) in London (Manchester take note after the sucessful London-Sabotarge in 2000), making it the first city to hold the Summer Olympic Games three times [would have been 4 times if they had not started WW2]. Australia, France, Germany and Greece have all hosted the Summer Olympic Games twice." Wiki summer Olympics. data.
After their supression by the Christian Administration of the European-Empire in circa 391 Ad-ce, the games remained forbidden until 1896 ce-ad (Athens Greece). Olympiads occur ever 4 years.