What is the total amount of decile with the authority of state around the Pokuru School and a roll smaller than 109?
CREATE TABLE "waipa_district" (
  "name" text,
  "years" text,
  "gender" text,
  "area" text,
  "authority" text,
  "decile" real,
  "roll" real
);
SELECT SUM("decile") FROM "waipa_district" WHERE "authority"='state' AND "name"='pokuru school' AND "roll"<109;