How many Vacators were listed when the district was North Carolina 3rd?
CREATE TABLE "table1_225095_4" (
  "district" text,
  "vacator" text,
  "reason_for_change" text,
  "successor" text,
  "date_successor_seated" text
);
SELECT COUNT("vacator") FROM "table1_225095_4" WHERE "district"='North Carolina 3rd';