What is the biggest number of the team who's owned by Jeff Gordon?
CREATE TABLE "full_time_teams" (
  "team" text,
  "car_s" text,
  "num" real,
  "driver_s" text,
  "primary_sponsor_s" text,
  "owner_s" text,
  "crew_chief" text
);
SELECT MAX("num") FROM "full_time_teams" WHERE "owner_s"='Jeff Gordon';