condition mean min max ZT0-3 27.487638 27.487638 27.487638 ZT4-7 27.0225345 27.0225345 27.0225345 ZT8-11 27.438602500000002 27.438602500000002 27.438602500000002 ZT12-15 26.1164735 26.1164735 26.1164735 ZT16-19 23.870570999999998 23.870570999999998 23.870570999999998 ZT20-23 25.539884 25.539884 25.539884