CREATE TABLE table_204_549 (id DECIMAL, "series\ number" TEXT, "key" TEXT, "composed" TEXT, "published" TEXT, "opus no." TEXT, "brown" TEXT, "kobylanska" TEXT, "chominski" TEXT, "dedication" TEXT, "notes" TEXT)

what was the top publishing year ?
SELECT "published" FROM table_204_549 GROUP BY "published" ORDER BY COUNT(*) DESC LIMIT 1
SELECT "published" FROM "table_204_549" GROUP BY "published" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1