What round was the draft pick of tight end with an Overall larger than 21?
CREATE TABLE "2002_new_england_patriots_draft_selectio" (
  "round" real,
  "overall" real,
  "player" text,
  "position" text,
  "college" text
);
SELECT COUNT("round") FROM "2002_new_england_patriots_draft_selectio" WHERE "position"='tight end' AND "overall">21;