condition mean min max ZT0-3 29.70915 29.70915 29.70915 ZT4-7 22.2877 22.2877 22.2877 ZT8-11 19.34095 19.34095 19.34095 ZT12-15 19.46585 19.46585 19.46585 ZT16-19 29.441 29.441 29.441 ZT20-23 31.784149999999997 31.784149999999997 31.784149999999997