condition mean min max ZT0-3 1.90885 1.7343349999999997 2.13838 ZT4-7 1.1543450000000002 1.1543450000000002 1.1543450000000002 ZT8-11 1.333035 1.333035 1.333035 ZT12-15 2.7532825 2.57051 2.936055 ZT16-19 2.076635 2.076635 2.076635 ZT20-23 2.0985650000000002 2.0985650000000002 2.0985650000000002