user: Question: how many countries had 21 points
Columns: ['Rk', 'Name', 'Country', 'Matches Played', 'Matches Won', 'Points', 'Prize Money (USD)']
Types: ['real', 'text', 'text', 'real', 'real', 'real', 'real']
Sample row: [1.0, 'Stan Smith', 'USA', 46.0, 41.0, 75.0, 154100.0]
SQL:

assistant: SELECT COUNT("Country") FROM "Table" WHERE "Points" = 21.0;