condition mean min max ZT0-3 4.27921 4.27921 4.27921 ZT4-7 4.0086949999999995 4.0086949999999995 4.0086949999999995 ZT8-11 4.258545 4.258545 4.258545 ZT12-15 3.8239799999999997 3.8239799999999997 3.8239799999999997 ZT16-19 4.658085 4.658085 4.658085 ZT20-23 4.1844 4.1844 4.1844