condition mean min max ZT0-3 2.4232199999999997 2.4232199999999997 2.4232199999999997 ZT4-7 2.5009195 2.5009195 2.5009195 ZT8-11 1.8066849999999999 1.8066849999999999 1.8066849999999999 ZT12-15 3.0264599999999997 3.0264599999999997 3.0264599999999997 ZT16-19 1.934745 1.934745 1.934745 ZT20-23 1.203289 1.203289 1.203289