WHAT IS THE LOWEST GRID FOR RETIREMENT, AND LAPS LARGER THAN 17?
CREATE TABLE "250cc_classification" (
  "rider" text,
  "manufacturer" text,
  "laps" real,
  "time_retired" text,
  "grid" real
);
SELECT MIN("grid") FROM "250cc_classification" WHERE "time_retired"='retirement' AND "laps">17;