I cant give an exact percentage because these are on grass in trainers and my pr in on a track in spikes, so those are 2 very different things, and i also dont time these. But basically i try to do extensive tempo so im guessing about 70% given the surface,. i just try to stay relaxed and stride it out.
I did do a workout at some point that was 7x200m on the track in trainers with 200m walk recovery and i timed these between 34-37 seconds