condition mean min max ZT0-3 4.400681666666666 1.857195 5.838065 ZT4-7 0.5289729999999999 0.5289729999999999 0.5289729999999999 ZT8-11 0.7997265 0.7997265 0.7997265 ZT12-15 1.0934175000000002 1.092165 1.09467 ZT16-19 2.27944 2.27944 2.27944 ZT20-23 5.9052500000000006 5.9052500000000006 5.9052500000000006