condition mean min max ZT0-3 1.0634753333333333 0.746556 1.274885 ZT4-7 0.8987795000000001 0.8987795000000001 0.8987795000000001 ZT8-11 0.648358 0.648358 0.648358 ZT12-15 0.819777 0.7985195 0.8410344999999999 ZT16-19 1.38992 1.38992 1.38992 ZT20-23 1.25679 1.25679 1.25679