condition mean min max ZT0-3 0.599691 0.599691 0.599691 ZT4-7 0.25182 0.25182 0.25182 ZT8-11 0.629532 0.629532 0.629532 ZT12-15 1.38922 1.38922 1.38922 ZT16-19 1.759255 1.759255 1.759255 ZT20-23 0.721304 0.721304 0.721304