Conversation so far:
When was Thor Heyerdahl's Kon-Tiki expedition?
Thor Heyerdahl became notable for his Kon-Tiki expedition in 1947.
Where did the Kon-Tiki expedition start from?
The expedition began in Peru.

Question: How many people were on the expedition?
Self-contained rewrite: How many people were on the Kon-Tiki expedition?