user: Question: How many nationalities are there for the 2011 Apertura?
Columns: ['Tournament', 'Player', 'Nationality', 'Team', 'Games played', 'Goals conceded', 'Coefficient']
Types: ['text', 'text', 'text', 'text', 'real', 'real', 'text']
Sample row: ['2008 Apertura', 'Gastón Sessa (1)', 'Argentine', 'Gimnasia (La Plata) (1)', 17.0, 14.0, '0.82']
SQL:

assistant: SELECT COUNT("Nationality") FROM "Table" WHERE "Tournament" = '2011 Apertura';