condition mean min max ZT0-3 12.946388333333333 8.949314999999999 16.037 ZT4-7 10.008500000000002 10.008500000000002 10.008500000000002 ZT8-11 14.82525 14.82525 14.82525 ZT12-15 24.344900000000003 21.47885 27.21095 ZT16-19 18.60595 18.60595 18.60595 ZT20-23 22.58905 22.58905 22.58905