user: Question: What is the total decile in the area of normanby with a roller smaller than 157?
Columns: ['Name', 'Years', 'Area', 'Authority', 'Decile', 'Roll']
Types: ['text', 'text', 'text', 'text', 'real', 'real']
Sample row: ['Auroa School', '1–8', 'Auroa', 'State', 8.0, 170.0]
SQL:

assistant: SELECT SUM("Decile") FROM "Table" WHERE "Area" = 'normanby' AND "Roll" < 157.0;