condition mean min max ZT0-3 2.7820400000000003 2.7820400000000003 2.7820400000000003 ZT4-7 2.10787 2.10787 2.10787 ZT8-11 1.756375 1.756375 1.756375 ZT12-15 3.21441 3.21441 3.21441 ZT16-19 5.747365 5.747365 5.747365 ZT20-23 3.09965 3.09965 3.09965