Table: buller_high_school
Columns: name
years
area
authority
decile
roll

Question: What is the average roll of a school with state authority and a decile of 9?
SQL: SELECT AVG("roll") FROM buller_high_school WHERE "authority" = 'state' AND "decile" = 9

Question: Which area has state authority and a roll fewer than 18?
SQL: SELECT "area" FROM buller_high_school WHERE "authority" = 'state' AND "roll" < 18

Question: What is the roll for the school with state authority and a decile of 9?
SQL: SELECT "roll" FROM buller_high_school WHERE "authority" = 'state' AND "decile" = 9

Question: What is the average decile of Westport South School?
SQL: SELECT AVG("decile") FROM buller_high_school WHERE "name" = 'westport south school'