Which sum of Seasons in league has a Best Position of 5th (2007)?
CREATE TABLE "participating_teams" (
  "pos_in_2007" text,
  "club" text,
  "city" text,
  "best_position" text,
  "seasons_in_league" real
);
SELECT SUM("seasons_in_league") FROM "participating_teams" WHERE "best_position"='5th (2007)';