user: Question: What is the average Decile with a State authority and a Name of Mapiu School?
Columns: ['Name', 'Years', 'Gender', 'Area', 'Authority', 'Decile', 'Roll']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'real']
Sample row: ['Aria School', '1–6', 'Coed', 'Aria', 'State', 5.0, 55.0]
SQL:

assistant: SELECT AVG("Decile") FROM "Table" WHERE "Authority" = 'State' AND "Name" = 'Mapiu School';