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 0.0 0.0 0.0 ZT16-19 0.03521126016666667 0.03069783233333333 0.039724688 ZT20-23 0.0 0.0 0.0