condition mean min max ZT0-3 5.737305 3.115605 8.359005 ZT4-7 5.26233 5.26233 5.26233 ZT8-11 0.443187 0.443187 0.443187 ZT12-15 0 0 0 ZT16-19 0.1091995 0.1091995 0.1091995 ZT20-23 0.109505 0.109505 0.109505