condition mean min max ZT0-3 1.8758975 1.48114 2.270655 ZT4-7 2.402055 2.402055 2.402055 ZT8-11 2.5804400000000003 2.5804400000000003 2.5804400000000003 ZT12-15 0 0 0 ZT16-19 3.2591349999999997 3.2591349999999997 3.2591349999999997 ZT20-23 3.19731 3.19731 3.19731