condition mean min max ZT0-3 1.2346241666666666 0.822086 1.4527299999999999 ZT4-7 1.0891395 1.0891395 1.0891395 ZT8-11 1.0762990000000001 1.0762990000000001 1.0762990000000001 ZT12-15 2.143345 1.9111500000000001 2.37554 ZT16-19 1.0710700000000002 1.0710700000000002 1.0710700000000002 ZT20-23 1.2053755 1.2053755 1.2053755