Task: Question Generation
Input (English): Mexico City remains the only Latin American city to host the Olympic Games, having held the Summer Olympics in 1968, winning bids against Buenos Aires, Lyon and Detroit. (This too will change thanks to Rio, 2016 Summer Games host). The city hosted the 1955 and 1975 Pan American Games, the last after Santiago and São Paulo withdrew. The ICF Flatwater Racing World Championships were hosted here in 1974 and 1994. Lucha libre is a Mexican style of wrestling, and is one of the more popular sports throughout the country. The main venues in the city are Arena México and Arena Coliseo.
Output (English): What year did Mexico City host the olympics?