condition mean min max ZT0-3 17.35 17.35 17.35 ZT4-7 21.0 21.0 21.0 ZT8-11 6.5 6.5 6.5 ZT12-15 2.6 2.6 2.6 ZT16-19 25.85 25.85 25.85 ZT20-23 21.1 21.1 21.1