condition mean min max ZT0-3 23.35 23.35 23.35 ZT4-7 16.7 16.7 16.7 ZT8-11 18.85 18.85 18.85 ZT12-15 7.05 7.05 7.05 ZT16-19 4.5 4.5 4.5 ZT20-23 12.05 12.05 12.05