What was the earliest year where USL PDL played in 3rd, Southeast season?
CREATE TABLE "year_by_year" (
  "year" real,
  "division" real,
  "league" text,
  "regular_season" text,
  "playoffs" text,
  "open_cup" text
);
SELECT MIN("year") FROM "year_by_year" WHERE "regular_season"='3rd, Southeast' AND "league"='USL PDL';