condition mean min max ZT0-3 0.031978 0.0 0.063956 ZT4-7 0.0248529 0.0248529 0.0248529 ZT8-11 0.0 0.0 0.0 ZT12-15 0.062010366666666664 0.05187133333333333 0.0721494 ZT16-19 0.027438599999999997 0.027438599999999997 0.027438599999999997 ZT20-23 0.043882000000000004 0.043882000000000004 0.043882000000000004