When the Winning score was –9 (69-72-68-70=279), what was the Margin of victory?
CREATE TABLE "pga_tour_wins_13" (
  "date" text,
  "tournament" text,
  "winning_score" text,
  "margin_of_victory" text,
  "runner_s_up" text
);
SELECT "margin_of_victory" FROM "pga_tour_wins_13" WHERE "winning_score"='–9 (69-72-68-70=279)';