condition mean min max ZT0-3 2.541356811 2.238853949 2.8438596730000003 ZT4-7 2.9105245245 2.793997353 3.027051696 ZT8-11 3.4872449892499997 3.403823348 3.5706666305 ZT12-15 4.9234155282500005 4.1845274875000005 5.662303569 ZT16-19 6.17085006025 4.6137404570000005 7.7279596635 ZT20-23 9.533693338749998 8.061428416 11.005958261499998