condition mean min max ZT0-3 1.9184911666666666 0.5962185 2.63396 ZT4-7 0.624731 0.624731 0.624731 ZT8-11 0.7711650000000001 0.7711650000000001 0.7711650000000001 ZT12-15 2.935365 1.83657 4.03416 ZT16-19 3.94576 3.94576 3.94576 ZT20-23 3.8310899999999997 3.8310899999999997 3.8310899999999997