condition mean min max ZT0-3 1.1617313333333334 0.698654 1.573005 ZT4-7 1.161988 1.161988 1.161988 ZT8-11 1.15946 1.15946 1.15946 ZT12-15 1.6438785 1.351027 1.93673 ZT16-19 1.780685 1.780685 1.780685 ZT20-23 3.0352699999999997 3.0352699999999997 3.0352699999999997