Name the sum of Hull number with portugal destination
CREATE TABLE "list_of_yachts" (
  "hull_no" real,
  "year" real,
  "project" text,
  "length_overall_in_meters_without_bowsprit" real,
  "name" text,
  "destination" text
);
SELECT SUM("hull_no") FROM "list_of_yachts" WHERE "destination"='portugal';