condition mean min max ZT0-3 25.70365 25.70365 25.70365 ZT4-7 23.70615 23.70615 23.70615 ZT8-11 20.287100000000002 20.287100000000002 20.287100000000002 ZT12-15 21.737000000000002 21.737000000000002 21.737000000000002 ZT16-19 18.26585 18.26585 18.26585 ZT20-23 22.528599999999997 22.528599999999997 22.528599999999997