user: Question: What is the total decile with an Area of whitianga, and a Roll smaller than 835?
Columns: ['Name', 'Years', 'Gender', 'Area', 'Authority', 'Decile', 'Roll']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'real']
Sample row: ['Colville School', '1–8', 'Coed', 'Colville', 'State', 4.0, 32.0]
SQL:

assistant: SELECT SUM("Decile") FROM "Table" WHERE "Area" = 'whitianga' AND "Roll" < 835.0;