condition mean min max ZT0-3 1.873504 1.873504 1.873504 ZT4-7 1.6601 1.6601 1.6601 ZT8-11 0.828902 0.828902 0.828902 ZT12-15 1.28049 1.28049 1.28049 ZT16-19 1.9382199999999998 1.9382199999999998 1.9382199999999998 ZT20-23 2.03858 2.03858 2.03858