condition mean min max ZT0-3 0.7486386666666667 0.616096 0.963048 ZT4-7 1.1523335000000001 1.1523335000000001 1.1523335000000001 ZT8-11 2.330115 2.330115 2.330115 ZT12-15 3.150365 2.29873 4.002 ZT16-19 3.967435 3.967435 3.967435 ZT20-23 1.7159900000000001 1.7159900000000001 1.7159900000000001