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 0.0080702125 0.0 0.016140425 ZT16-19 0.011395016666666667 0.0 0.022790033333333334 ZT20-23 0 0 0