CREATE TABLE table_204_156 (id DECIMAL, "year" DECIMAL, "crystal bicycle\ ( best professional cyclist ) " TEXT, "best young rider" TEXT, "best manager" TEXT, "crystal drop of sweat\ ( best helper ) " TEXT)

what is the average number of times johan museeuw starred ?
SELECT COUNT(*) FROM table_204_156 WHERE "crystal bicycle\n(best professional cyclist)" = 'johan museeuw'
SELECT COUNT(*) FROM "table_204_156" WHERE "crystal bicycle\n(best professional cyclist)" = 'johan museeuw'