condition mean min max ZT0-3 1.5608433333333334 1.5116200000000002 1.595215 ZT4-7 1.2201755 1.2201755 1.2201755 ZT8-11 2.0310360000000003 2.0310360000000003 2.0310360000000003 ZT12-15 2.2914625 1.694015 2.88891 ZT16-19 1.64445 1.64445 1.64445 ZT20-23 1.86035 1.86035 1.86035