user: Question: What country offered a prize of 66400 US dollars?
Columns: ['Rk', 'Name', 'Country', 'Matches Played', 'Matches Won', 'Points', 'Prize Money (USD)']
Types: ['real', 'text', 'text', 'real', 'real', 'real', 'real']
Sample row: [1.0, 'Ken Rosewall', 'AUS', 42.0, 34.0, 53.0, 66400.0]
SQL:

assistant: SELECT "Country" FROM "Table" WHERE "Prize Money (USD)" = 66400.0;