condition mean min max ZT0-3 14.613353333333333 9.82551 17.31005 ZT4-7 8.679465 8.679465 8.679465 ZT8-11 7.931345 7.931345 7.931345 ZT12-15 16.996299999999998 15.12725 18.86535 ZT16-19 15.95205 15.95205 15.95205 ZT20-23 20.4782 20.4782 20.4782