condition mean min max ZT0-3 6.4141675000000005 5.57549 7.252845000000001 ZT4-7 3.0615449999999997 3.0615449999999997 3.0615449999999997 ZT8-11 2.8510099999999996 2.8510099999999996 2.8510099999999996 ZT12-15 0 0 0 ZT16-19 4.827705 4.827705 4.827705 ZT20-23 4.46194 4.46194 4.46194