condition mean min max ZT0-3 3.904675 3.904675 3.904675 ZT4-7 3.453875 3.453875 3.453875 ZT8-11 4.335735 4.335735 4.335735 ZT12-15 3.0855449999999998 3.0855449999999998 3.0855449999999998 ZT16-19 3.8938550000000003 3.8938550000000003 3.8938550000000003 ZT20-23 2.55539 2.55539 2.55539