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 0.013025604166666666 0.008241875 0.017809333333333333 ZT16-19 0.0 0.0 0.0 ZT20-23 0 0 0