condition mean min max ZT0-3 3.8813250000000004 0.0 8.765555 ZT4-7 8.44627 8.44627 8.44627 ZT8-11 8.664935 8.664935 8.664935 ZT12-15 2.81605 0.0 5.6321 ZT16-19 5.38975 5.38975 5.38975 ZT20-23 6.08255 6.08255 6.08255