condition mean min max ZT0-3 27.75 27.75 27.75 ZT4-7 4.0 4.0 4.0 ZT8-11 2.7 2.7 2.7 ZT12-15 22.0 22.0 22.0 ZT16-19 18.35 18.35 18.35 ZT20-23 25.75 25.75 25.75