condition mean min max ZT0-3 1.852805 1.852805 1.852805 ZT4-7 1.4002249999999998 1.4002249999999998 1.4002249999999998 ZT8-11 1.7933949999999999 1.7933949999999999 1.7933949999999999 ZT12-15 1.9859 1.9859 1.9859 ZT16-19 3.0548 3.0548 3.0548 ZT20-23 2.3263749999999996 2.3263749999999996 2.3263749999999996