condition mean min max ZT0-3 16.75 16.75 16.75 ZT4-7 23.0 23.0 23.0 ZT8-11 14.75 14.75 14.75 ZT12-15 20.299999999999997 20.299999999999997 20.299999999999997 ZT16-19 8.95 8.95 8.95 ZT20-23 20.55 20.55 20.55