What is the average number of laps that were made when the race took a time of +48.325?
CREATE TABLE "moto_gp_classification" (
  "rider" text,
  "manufacturer" text,
  "laps" real,
  "time_retired" text,
  "grid" real
);
SELECT AVG("laps") FROM "moto_gp_classification" WHERE "time_retired"='+48.325';