What is the overall pick average with the pick # lower than 15?
CREATE TABLE "indianapolis_colts_draft_history" (
  "round" real,
  "pick_num" real,
  "overall" real,
  "name" text,
  "position" text,
  "college" text
);
SELECT AVG("overall") FROM "indianapolis_colts_draft_history" WHERE "pick_num"<15;