condition mean min max ZT0-3 442.071719 442.071719 442.071719 ZT4-7 422.962045 422.962045 422.962045 ZT8-11 250.8406655 250.8406655 250.8406655 ZT12-15 480.04481499999997 480.04481499999997 480.04481499999997 ZT16-19 565.693595 565.693595 565.693595 ZT20-23 1040.6607325 1040.6607325 1040.6607325