Name the number of womens doubles for 2011 rio de janeiro
CREATE TABLE "brazil_open" (
  "year_location" text,
  "mens_singles" text,
  "womens_singles" text,
  "mens_doubles" text,
  "womens_doubles" text
);
SELECT COUNT("womens_doubles") FROM "brazil_open" WHERE "year_location"='2011 Rio de Janeiro';