condition mean min max ZT0-3 3.13518 2.68709 3.5832699999999997 ZT4-7 4.436175 4.436175 4.436175 ZT8-11 3.67746 3.67746 3.67746 ZT12-15 0 0 0 ZT16-19 4.0008799999999995 4.0008799999999995 4.0008799999999995 ZT20-23 4.685005 4.685005 4.685005