user: Question: What is the number of contestants who are aged exactly 18?
Columns: ['Country', 'Contestant', 'Age', 'Height (cm)', 'Height (ft)', 'Hometown']
Types: ['text', 'text', 'real', 'real', 'text', 'text']
Sample row: ['Argentina', 'Yanina Ruiz', 24.0, 175.0, '5\'9"', 'Morón']
SQL:

assistant: SELECT COUNT("Contestant") FROM "Table" WHERE "Age" = 18.0;