condition mean min max ZT0-3 20.475983333333335 16.519350000000003 23.352249999999998 ZT4-7 14.698450000000001 14.698450000000001 14.698450000000001 ZT8-11 12.69115 12.69115 12.69115 ZT12-15 20.630275 19.254800000000003 22.00575 ZT16-19 19.936349999999997 19.936349999999997 19.936349999999997 ZT20-23 25.80525 25.80525 25.80525