What is the margin of victory for the winning score of −10 (71-65-68-70=274)?
CREATE TABLE "pga_tour_wins_5" (
  "date" text,
  "tournament" text,
  "winning_score" text,
  "margin_of_victory" text,
  "runner_s_up" text
);
SELECT "margin_of_victory" FROM "pga_tour_wins_5" WHERE "winning_score"='−10 (71-65-68-70=274)';