What is the Margin when the Winning score is +8 (70-69-70-75=284)?
CREATE TABLE "wins_11" (
  "year" real,
  "championship" text,
  "winning_score" text,
  "margin" text,
  "runner_s_up" text
);
SELECT "margin" FROM "wins_11" WHERE "winning_score"='+8 (70-69-70-75=284)';