user: Question: How many athletes were named Federico Muller?
Columns: ['Athlete', 'Event', 'Elimination Poule', 'Round of 16', 'Quarterfinals', 'Semifinals', 'Final']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['José Domínguez', 'Individual épée', '3 V - 2 D', 'W Kelsey ( USA ) L 8 - 15', 'Did not advance', 'Did not advance', 'Did not advance']
SQL:

assistant: SELECT COUNT("Quarterfinals") FROM "Table" WHERE "Athlete" = 'Federico Muller';