Which #/ County has a Year Joined larger than 1926, and a Previous Conference of olympic?
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 "num_county" FROM "membership" WHERE "year_joined">1926 AND "previous_conference"='olympic';