condition mean min max ZT0-3 3.6312699999999998 3.6312699999999998 3.6312699999999998 ZT4-7 3.0748800000000003 3.0748800000000003 3.0748800000000003 ZT8-11 3.3700650000000003 3.3700650000000003 3.3700650000000003 ZT12-15 3.47806 3.47806 3.47806 ZT16-19 4.08141 4.08141 4.08141 ZT20-23 3.2195666666666667 3.2195666666666667 3.2195666666666667