what is the total number of building for address on 201 1st avenue south
CREATE TABLE "buildings_completed_as_of_february_2011" (
  "rank" real,
  "building" text,
  "address" text,
  "height" text,
  "storeys" real,
  "completed" real
);
SELECT COUNT("building") FROM "buildings_completed_as_of_february_2011" WHERE "address"='201 1st Avenue South';