condition mean min max ZT0-3 5.825968333333334 3.231825 10.242635 ZT4-7 1.631135 1.631135 1.631135 ZT8-11 1.964655 1.964655 1.964655 ZT12-15 3.6278425 3.43816 3.817525 ZT16-19 3.210575 3.210575 3.210575 ZT20-23 5.754965 5.754965 5.754965