condition mean min max ZT0-3 0.0 0.0 0.0 ZT4-7 0.0 0.0 0.0 ZT8-11 0.0 0.0 0.0 ZT12-15 0.0390313435 0.0 0.078062687 ZT16-19 0.0 0.0 0.0 ZT20-23 0.018502629833333336 0.0 0.03700525966666667