condition mean min max ZT0-3 23.9 23.9 23.9 ZT4-7 2.7 2.7 2.7 ZT8-11 14.85 14.85 14.85 ZT12-15 2.3 2.3 2.3 ZT16-19 13.299999999999999 13.299999999999999 13.299999999999999 ZT20-23 16.05 16.05 16.05