user: Question: How many periods had 15 goals?
Columns: ['Name', 'Position', 'Period', 'Appearances¹', 'Goals¹', 'Nationality²']
Types: ['text', 'text', 'text', 'real', 'real', 'text']
Sample row: ['Robert Jacques', 'Forward', '1985 – 1986', 28.0, 6.0, 'France']
SQL:

assistant: SELECT COUNT("Period") FROM "Table" WHERE "Goals¹" = 15.0;