condition mean min max ZT0-3 23.587766666666667 19.1644 26.836750000000002 ZT4-7 22.7838 22.7838 22.7838 ZT8-11 20.6873 20.6873 20.6873 ZT12-15 34.055225 26.728499999999997 41.38195 ZT16-19 37.926249999999996 37.926249999999996 37.926249999999996 ZT20-23 32.859 32.859 32.859