condition mean min max ZT0-3 15.222516 15.222516 15.222516 ZT4-7 14.685076 14.685076 14.685076 ZT8-11 14.027203499999999 14.027203499999999 14.027203499999999 ZT12-15 15.352268500000001 15.352268500000001 15.352268500000001 ZT16-19 17.249965500000002 17.249965500000002 17.249965500000002 ZT20-23 18.350404 18.350404 18.350404