condition mean min max ZT0-3 39.75 39.75 39.75 ZT4-7 13.9 13.9 13.9 ZT8-11 35.65 35.65 35.65 ZT12-15 25.799999999999997 25.799999999999997 25.799999999999997 ZT16-19 15.950000000000001 15.950000000000001 15.950000000000001 ZT20-23 62.05 62.05 62.05