user: Question: What was the nationality of the winner for the 20th Edition?
Columns: ['Edition', 'Date', 'Winner', 'Country', 'Time ( h : m : s )']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['66th', 'December 2, 2012', 'Joseph Gitau', 'Kenya', '2:06:58']
SQL:

assistant: SELECT "Country" FROM "Table" WHERE "Edition" = '20th';