condition mean min max ZT0-3 5.699999999999999 5.699999999999999 5.699999999999999 ZT4-7 2.5 2.5 2.5 ZT8-11 5.35 5.35 5.35 ZT12-15 3.95 3.95 3.95 ZT16-19 6.1 6.1 6.1 ZT20-23 6.3500000000000005 6.3500000000000005 6.3500000000000005