condition mean min max ZT0-3 1.257275 1.257275 1.257275 ZT4-7 0.8013635 0.8013635 0.8013635 ZT8-11 0.487749 0.487749 0.487749 ZT12-15 0.8975759999999999 0.8975759999999999 0.8975759999999999 ZT16-19 1.38341 1.38341 1.38341 ZT20-23 1.340977 1.340977 1.340977