condition mean min max ZT0-3 2.0176366666666667 0.0 6.05291 ZT4-7 3.822075 3.822075 3.822075 ZT8-11 1.977245 1.977245 1.977245 ZT12-15 0.0 0.0 0.0 ZT16-19 0.0 0.0 0.0 ZT20-23 2.0767 2.0767 2.0767