condition mean min max ZT0-3 3.0464200000000003 3.0464200000000003 3.0464200000000003 ZT4-7 1.67248 1.67248 1.67248 ZT8-11 2.1760599999999997 2.1760599999999997 2.1760599999999997 ZT12-15 1.9372250000000002 1.9372250000000002 1.9372250000000002 ZT16-19 2.1411249999999997 2.1411249999999997 2.1411249999999997 ZT20-23 3.42743 3.42743 3.42743