Which year has an Engine(s) of yamaha v8?
CREATE TABLE "complete_world_championship_formula_one_" (
  "year" real,
  "chassis" text,
  "engine_s" text,
  "tyres" text,
  "points" real
);
SELECT "year" FROM "complete_world_championship_formula_one_" WHERE "engine_s"='yamaha v8';