condition mean min max ZT0-3 3.0809249999999997 3.0809249999999997 3.0809249999999997 ZT4-7 1.2628065 1.2628065 1.2628065 ZT8-11 1.77383 1.77383 1.77383 ZT12-15 3.089525 3.089525 3.089525 ZT16-19 8.16743 8.16743 8.16743 ZT20-23 3.724985 3.724985 3.724985