What is the winners share ($) that has u.s. open as the tournament?
CREATE TABLE "tournament_results" (
  "date" text,
  "tournament" text,
  "location" text,
  "winner" text,
  "score" text,
  "winner_s_share" text
);
SELECT "winner_s_share" FROM "tournament_results" WHERE "tournament"='u.s. open';