condition mean min max ZT0-3 2.0036199999999997 2.0036199999999997 2.0036199999999997 ZT4-7 1.8112 1.8112 1.8112 ZT8-11 1.78878 1.78878 1.78878 ZT12-15 3.043895 3.043895 3.043895 ZT16-19 3.7005799999999995 3.7005799999999995 3.7005799999999995 ZT20-23 1.67446 1.67446 1.67446