condition mean min max ZT0-3 20.4 20.4 20.4 ZT4-7 3.9 3.9 3.9 ZT8-11 19.0 19.0 19.0 ZT12-15 23.85 23.85 23.85 ZT16-19 36.25 36.25 36.25 ZT20-23 25.7 25.7 25.7