condition mean min max ZT0-3 14.4 14.4 14.4 ZT4-7 19.5 19.5 19.5 ZT8-11 2.6500000000000004 2.6500000000000004 2.6500000000000004 ZT12-15 19.799999999999997 19.799999999999997 19.799999999999997 ZT16-19 31.200000000000003 31.200000000000003 31.200000000000003 ZT20-23 38.1 38.1 38.1