condition mean min max ZT0-3 7.215845 5.401985 9.105805 ZT4-7 4.75638 4.75638 4.75638 ZT8-11 4.942015 4.942015 4.942015 ZT12-15 9.651135 7.61722 11.68505 ZT16-19 7.64749 7.64749 7.64749 ZT20-23 9.69642 9.69642 9.69642