condition mean min max ZT0-3 1.838475 1.838475 1.838475 ZT4-7 1.7125050000000002 1.7125050000000002 1.7125050000000002 ZT8-11 1.8496549999999998 1.8496549999999998 1.8496549999999998 ZT12-15 3.085205 3.085205 3.085205 ZT16-19 3.14499 3.14499 3.14499 ZT20-23 1.6801849999999998 1.6801849999999998 1.6801849999999998