condition mean min max ZT0-3 2.1671 2.1095550000000003 2.2246449999999998 ZT4-7 2.870595 2.870595 2.870595 ZT8-11 3.47395 3.47395 3.47395 ZT12-15 0 0 0 ZT16-19 2.6670800000000003 2.6670800000000003 2.6670800000000003 ZT20-23 3.57504 3.57504 3.57504