What was the earliest week the team played the chicago cardinals in front of less than 25,312?
CREATE TABLE "regular_season_schedule" (
  "week" real,
  "date" text,
  "opponent" text,
  "result" text,
  "attendance" real
);
SELECT MIN("week") FROM "regular_season_schedule" WHERE "opponent"='chicago cardinals' AND "attendance"<'25,312';