What is the average year for a Saar of FK Pirmasens and Hessen of Wormatia Worms?
CREATE TABLE "1928_to_1933" (
  "year" real,
  "main" text,
  "hessen" text,
  "rhein" text,
  "saar" text
);
SELECT AVG("year") FROM "1928_to_1933" WHERE "saar"='fk pirmasens' AND "hessen"='wormatia worms';