What is the largest win percentage when John Gartin is coach, the record is 11-0, and the year is 2009?
CREATE TABLE "season_by_season_results" (
  "year" text,
  "coach" text,
  "crew" text,
  "record" text,
  "win_pct" real
);
SELECT MAX("win_pct") FROM "season_by_season_results" WHERE "coach"='john gartin' AND "record"='11-0' AND "year"='2009';