condition mean min max ZT0-3 20.75 20.75 20.75 ZT4-7 12.7 12.7 12.7 ZT8-11 28.299999999999997 28.299999999999997 28.299999999999997 ZT12-15 27.35 27.35 27.35 ZT16-19 46.5 46.5 46.5 ZT20-23 20.85 20.85 20.85