condition mean min max ZT0-3 4.135136666666667 2.86334 5.379615 ZT4-7 1.8316 1.8316 1.8316 ZT8-11 0.8797619999999999 0.8797619999999999 0.8797619999999999 ZT12-15 3.58407 2.42638 4.74176 ZT16-19 7.3341 7.3341 7.3341 ZT20-23 7.076215 7.076215 7.076215