What year did finish 1st in LMP1 class?
CREATE TABLE "complete_24_hours_of_le_mans_results" (
  "year" real,
  "team" text,
  "co_drivers" text,
  "class" text,
  "laps" real,
  "pos" text,
  "class_pos" text
);
SELECT AVG("year") FROM "complete_24_hours_of_le_mans_results" WHERE "class"='lmp1' AND "class_pos"='1st';