What was the winning score on May 3, 1998?
CREATE TABLE "pga_tour_wins_13" (
  "date" text,
  "tournament" text,
  "winning_score" text,
  "margin_of_victory" text,
  "runner_s_up" text
);
SELECT "winning_score" FROM "pga_tour_wins_13" WHERE "date"='may 3, 1998';