CREATE TABLE table_203_400 (id DECIMAL, "district" TEXT, "vacator" TEXT, "reason for change" TEXT, "successor" TEXT, "date successor\ seated" TEXT)

how many of the changes happened before june of 1986 ?
SELECT COUNT(*) FROM table_203_400 WHERE "date successor\nseated" < 1986 OR ("date successor\nseated" = 1986 AND "date successor\nseated" < 6)
SELECT COUNT(*) FROM "table_203_400" WHERE "date successor\nseated" < 1986