condition mean min max ZT0-3 15.709433065 15.5431801 15.87568603 ZT4-7 14.13183757 12.083878615 16.179796525 ZT8-11 16.969301797500002 15.38225681 18.556346785000002 ZT12-15 22.25979978 20.942328545 23.577271015 ZT16-19 27.770011765 25.51198647 30.028037060000003 ZT20-23 33.812695309999995 33.115022775 34.510367845