condition mean min max ZT0-3 17.6 17.6 17.6 ZT4-7 1.7 1.7 1.7 ZT8-11 16.85 16.85 16.85 ZT12-15 21.65 21.65 21.65 ZT16-19 35.75 35.75 35.75 ZT20-23 8.95 8.95 8.95