Those are indeed remarkable numbers and are perhaps incredible for your Super-Fox. It's generally known that pattern efficiency (percentage) in 12-gauge guns with ducking size shot will drop off by 1 to 1.5% per yard in going from 40 to 60 yards. Witness that Capt Charles Askins reported on one exceptional Super-Fox that did 88% patterns at 40 yards, and 52% at 60 yards. That was with 3-inch/1/3/8 ounce Super-X's in an early overbored and heavily choked gun. Working backwards from your "almost 90%" at 55 yards, that would make your Super doing 100% at 40 yards, and still 100% at about 45 yards. Wow! One for the Fox record books!