condition mean min max ZT0-3 1.3945698333333334 1.0616005 1.9884 ZT4-7 1.36572 1.36572 1.36572 ZT8-11 1.2110699999999999 1.2110699999999999 1.2110699999999999 ZT12-15 3.61346 3.4964649999999997 3.730455 ZT16-19 3.41267 3.41267 3.41267 ZT20-23 3.1236800000000002 3.1236800000000002 3.1236800000000002