user: Question: Which Decile has Years of –, and a Gender of Coed?
Columns: ['Name', 'Years', 'Gender', 'Area', 'Authority', 'Decile']
Types: ['text', 'text', 'text', 'text', 'text', 'real']
Sample row: ['Arthur Miller School', '1–6', 'Coed', 'Taradale', 'State', 8.0]
SQL:

assistant: SELECT "Decile" FROM "Table" WHERE "Years" = '–' AND "Gender" = 'Coed';