condition mean min max ZT0-3 6.23781 5.563835 7.516985 ZT4-7 4.59417 4.59417 4.59417 ZT8-11 3.215275 3.215275 3.215275 ZT12-15 3.8245825 3.69658 3.952585 ZT16-19 4.8441 4.8441 4.8441 ZT20-23 5.24381 5.24381 5.24381