What is the lowest round of bob caldwell, who has a pick greater than 7 and an overall larger than 162?
CREATE TABLE "washington_redskins_draft_history" (
  "round" real,
  "pick" real,
  "overall" real,
  "name" text,
  "position" text,
  "college" text
);
SELECT MIN("round") FROM "washington_redskins_draft_history" WHERE "pick">7 AND "name"='bob caldwell' AND "overall">162;