How many wins for bikes with under 54 points, team yamaha, a 250cc bike, and before 1977?
CREATE TABLE "grand_prix_motorcycle_racing_results" (
  "year" real,
  "class" text,
  "team" text,
  "points" real,
  "wins" real
);
SELECT COUNT("wins") FROM "grand_prix_motorcycle_racing_results" WHERE "points"<54 AND "team"='yamaha' AND "class"='250cc' AND "year"<1977;