condition mean min max ZT0-3 15.583233333333332 14.91535 16.34435 ZT4-7 7.493165 7.493165 7.493165 ZT8-11 1.857625 1.857625 1.857625 ZT12-15 1.826626 1.241247 2.412005 ZT16-19 1.3132759999999999 1.3132759999999999 1.3132759999999999 ZT20-23 4.349945 4.349945 4.349945