Regardless of the Percentage, that 1.5 miles per hour would mean that the next fastest man after Ricky Ashworth would have finished 40.4 metres behind him, which is extremely significant in a Speedway race!!
I was lucky enough to be there last season and I remember Jason Crump describing it as being 100mph into a right angled bend. The track is so huge they only do three laps, and the "safety fence" is solid concrete. A great show though with extreme Motocross and midgets in the bill. Wish I was there this time.