condition mean min max ZT0-3 1.1510263333333335 0.9872430000000001 1.4446400000000001 ZT4-7 0.8298215 0.8298215 0.8298215 ZT8-11 1.034077 1.034077 1.034077 ZT12-15 1.21560275 1.2071005 1.224105 ZT16-19 1.1374745 1.1374745 1.1374745 ZT20-23 1.2514850000000002 1.2514850000000002 1.2514850000000002