In 1971, how many total points did the entrant stp march have?
CREATE TABLE "complete_formula_one_results" (
  "year" real,
  "entrant" text,
  "chassis" text,
  "engine" text,
  "points" real
);
SELECT COUNT("points") FROM "complete_formula_one_results" WHERE "entrant"='stp march' AND "year">1971;