condition mean min max ZT0-3 3.434571666666667 3.20866 3.6172050000000002 ZT4-7 3.1977399999999996 3.1977399999999996 3.1977399999999996 ZT8-11 2.852055 2.852055 2.852055 ZT12-15 2.42372 2.287465 2.5599749999999997 ZT16-19 2.397675 2.397675 2.397675 ZT20-23 3.903085 3.903085 3.903085