What was the winning score of the Valero Texas Open?
CREATE TABLE "pga_tour_wins_12" (
  "date" text,
  "tournament" text,
  "winning_score" text,
  "margin_of_victory" text,
  "runner_s_up" text
);
SELECT "winning_score" FROM "pga_tour_wins_12" WHERE "tournament"='valero texas open';