condition mean min max ZT0-3 137.378922 137.378922 137.378922 ZT4-7 159.59078799999997 159.59078799999997 159.59078799999997 ZT8-11 161.391746 161.391746 161.391746 ZT12-15 160.7367885 160.7367885 160.7367885 ZT16-19 198.5111145 198.5111145 198.5111145 ZT20-23 220.2647855 220.2647855 220.2647855