condition mean min max ZT0-3 61.472231 61.472231 61.472231 ZT4-7 83.62213 83.62213 83.62213 ZT8-11 72.2889145 72.2889145 72.2889145 ZT12-15 80.73173299999999 80.73173299999999 80.73173299999999 ZT16-19 83.885479 83.885479 83.885479 ZT20-23 73.7488205 73.7488205 73.7488205