condition mean min max ZT0-3 7.75 7.75 7.75 ZT4-7 4.0 4.0 4.0 ZT8-11 52.05 52.05 52.05 ZT12-15 19.1 19.1 19.1 ZT16-19 36.5 36.5 36.5 ZT20-23 28.35 28.35 28.35