condition mean min max ZT0-3 1.1872833333333335 0.267654 2.585395 ZT4-7 6.528615 6.528615 6.528615 ZT8-11 3.587895 3.587895 3.587895 ZT12-15 3.2322249999999997 2.462405 4.002045 ZT16-19 1.627275 1.627275 1.627275 ZT20-23 0.524153 0.524153 0.524153