condition mean min max ZT0-3 2.6056299999999997 2.6056299999999997 2.6056299999999997 ZT4-7 1.47286 1.47286 1.47286 ZT8-11 1.73844 1.73844 1.73844 ZT12-15 2.076415 2.076415 2.076415 ZT16-19 4.01634 4.01634 4.01634 ZT20-23 2.52715 2.52715 2.52715