condition mean min max ZT0-3 2.0343413167500004 1.6671920480000002 2.4014905855000004 ZT4-7 1.53282239775 1.5190731275 1.546571668 ZT8-11 2.53356993225 1.916586761 3.1505531035 ZT12-15 3.10220016325 3.021814485 3.1825858415 ZT16-19 3.075926038 2.5609262445 3.5909258315 ZT20-23 5.3179802725 4.0944533725 6.5415071725