How many seats does leader Raymond McCartney have?
CREATE TABLE "leaders_in_the_northern_ireland_assembel" (
  "leader" text,
  "party" text,
  "leader_s_seat" text,
  "number_of_seats" real,
  "leader_since" text
);
SELECT SUM("number_of_seats") FROM "leaders_in_the_northern_ireland_assembel" WHERE "leader"='raymond mccartney';