condition mean min max ZT0-3 16.978550000000002 11.3294 20.580750000000002 ZT4-7 3.2654199999999998 3.2654199999999998 3.2654199999999998 ZT8-11 1.9089649999999998 1.9089649999999998 1.9089649999999998 ZT12-15 2.0935474999999997 1.594515 2.59258 ZT16-19 2.38546 2.38546 2.38546 ZT20-23 8.188905 8.188905 8.188905