condition mean min max ZT0-3 19.75015 19.75015 19.75015 ZT4-7 13.8584 13.8584 13.8584 ZT8-11 12.23755 12.23755 12.23755 ZT12-15 17.8486 17.8486 17.8486 ZT16-19 18.093049999999998 18.093049999999998 18.093049999999998 ZT20-23 19.9506 19.9506 19.9506