condition mean min max ZT0-3 1.007862 1.007862 1.007862 ZT4-7 1.4866 1.4866 1.4866 ZT8-11 1.3539299999999999 1.3539299999999999 1.3539299999999999 ZT12-15 1.27389 1.27389 1.27389 ZT16-19 2.38131 2.38131 2.38131 ZT20-23 2.31228 2.31228 2.31228