condition mean min max ZT0-3 3.7362386919999997 3.4370004539999996 4.03547693 ZT4-7 1.87766189875 1.8598783970000001 1.8954454004999999 ZT8-11 1.4674554359999998 1.09752004 1.8373908319999999 ZT12-15 2.857505312 2.121964833 3.5930457909999998 ZT16-19 3.19123495725 2.8756354975 3.5068344170000003 ZT20-23 3.3048267987499997 3.1475252234999997 3.4621283739999997