condition mean min max ZT0-3 1.5840313333333333 1.214769 1.9252449999999999 ZT4-7 1.541535 1.541535 1.541535 ZT8-11 2.1754100000000003 2.1754100000000003 2.1754100000000003 ZT12-15 1.84746 1.7650800000000002 1.92984 ZT16-19 1.94969 1.94969 1.94969 ZT20-23 1.54557 1.54557 1.54557