condition mean min max ZT0-3 3.6985799999999998 3.6985799999999998 3.6985799999999998 ZT4-7 2.8633249999999997 2.8633249999999997 2.8633249999999997 ZT8-11 3.4463150000000002 3.4463150000000002 3.4463150000000002 ZT12-15 4.68013 4.68013 4.68013 ZT16-19 5.803825 5.803825 5.803825 ZT20-23 4.23798 4.23798 4.23798