condition mean min max ZT0-3 0.15502916666666666 0.153577 0.157661 ZT4-7 0.6131725 0.6131725 0.6131725 ZT8-11 0.9504195 0.9504195 0.9504195 ZT12-15 3.9920975000000003 3.625065 4.35913 ZT16-19 3.6095699999999997 3.6095699999999997 3.6095699999999997 ZT20-23 0.33931999999999995 0.33931999999999995 0.33931999999999995