CREATE TABLE table_73392 ("District" TEXT, "Vacator" TEXT, "Reason for change" TEXT, "Successor" TEXT, "Date successor seated" TEXT)

Name the date successor seated for delegate seat established
SELECT "Date successor seated" FROM table_73392 WHERE "Reason for change" = 'Delegate seat established'
SELECT "Date successor seated" FROM "table_73392" WHERE "Reason for change" = 'Delegate seat established'