CREATE TABLE "classification" (
  "driver" text,
  "constructor" text,
  "laps" real,
  "time_retired" text,
  "grid" real
);

Question: In grid 15, how many laps were there before ending with a time of exhaust?
SQL: SELECT SUM("laps") FROM "classification" WHERE "time_retired"='exhaust' AND "grid"<15;