condition mean min max ZT0-3 0.398924 0.398924 0.398924 ZT4-7 0.28835515 0.28835515 0.28835515 ZT8-11 0.312233 0.312233 0.312233 ZT12-15 0.36909899999999995 0.36909899999999995 0.36909899999999995 ZT16-19 0.5016195 0.5016195 0.5016195 ZT20-23 0.387685 0.387685 0.387685