CREATE TABLE "complete_formula_one_world_championship_" (
  "year" real,
  "entrant" text,
  "chassis" text,
  "engine" text,
  "points" real
);

Question: How many points did Connaught Type A chassis earn on average before 1955?
SQL: SELECT AVG("points") FROM "complete_formula_one_world_championship_" WHERE "year"<1955 AND "chassis"='connaught type a';