condition mean min max ZT0-3 1.05962 1.05962 1.05962 ZT4-7 0.94543 0.94543 0.94543 ZT8-11 1.28969 1.28969 1.28969 ZT12-15 1.88631 1.88631 1.88631 ZT16-19 3.4662533333333334 3.4662533333333334 3.4662533333333334 ZT20-23 1.8494499999999998 1.8494499999999998 1.8494499999999998