condition mean min max ZT0-3 21.8 21.8 21.8 ZT4-7 3.8 3.8 3.8 ZT8-11 28.75 28.75 28.75 ZT12-15 4.45 4.45 4.45 ZT16-19 20.9 20.9 20.9 ZT20-23 21.15 21.15 21.15