user: Question: Name the average decile for State authority and area of Fernridge
Columns: ['Name', 'Years', 'Gender', 'Area', 'Authority', 'Decile']
Types: ['text', 'text', 'text', 'text', 'text', 'real']
Sample row: ['Chanel College', '7–13', 'Coed', 'Masterton', 'Integrated', 5.0]
SQL:

assistant: SELECT AVG("Decile") FROM "Table" WHERE "Authority" = 'State' AND "Area" = 'Fernridge';