What was the highest grid value for riders with manufacturer of Aprilia and time of +1.660?
CREATE TABLE "125cc_classification" (
  "rider" text,
  "manufacturer" text,
  "laps" real,
  "time_retired" text,
  "grid" real
);
SELECT MAX("grid") FROM "125cc_classification" WHERE "manufacturer"='aprilia' AND "time_retired"='+1.660';