Which Previous Conference has an IHSAA Class/ Football/ Soccer of 4a/5a/2a, and a Year Joined larger than 1926?
CREATE TABLE "membership" (
  "school" text,
  "location" text,
  "mascot" text,
  "num_county" text,
  "enrollment" real,
  "ihsaa_class_football_soccer" text,
  "year_joined" real,
  "previous_conference" text
);
SELECT "previous_conference" FROM "membership" WHERE "ihsaa_class_football_soccer"='4a/5a/2a' AND "year_joined">1926;