How many women doubles teams competed in the same year as when Jamie van Hooijdonk competed in men singles?
CREATE TABLE "21st_century" (
  "season" real,
  "mens_singles" text,
  "womens_singles" text,
  "mens_doubles" text,
  "womens_doubles" text,
  "mixed_doubles" text
);
SELECT COUNT("womens_doubles") FROM "21st_century" WHERE "mens_singles"='Jamie van Hooijdonk';