What years does Kakahi school, with a decile of 3, have?
CREATE TABLE "ruapehu_district" (
  "name" text,
  "years" text,
  "area" text,
  "authority" text,
  "decile" real,
  "roll" real
);
SELECT "years" FROM "ruapehu_district" WHERE "decile"=3 AND "name"='kakahi school';