condition mean min max ZT0-3 0.8840093333333333 0.439454 1.3121049999999999 ZT4-7 0.42307 0.42307 0.42307 ZT8-11 0.3278805 0.3278805 0.3278805 ZT12-15 1.55921175 1.5558235 1.5626 ZT16-19 1.241395 1.241395 1.241395 ZT20-23 1.6388449999999999 1.6388449999999999 1.6388449999999999