condition mean min max ZT0-3 18.15 18.15 18.15 ZT4-7 20.9 20.9 20.9 ZT8-11 33.45 33.45 33.45 ZT12-15 39.099999999999994 39.099999999999994 39.099999999999994 ZT16-19 23.799999999999997 23.799999999999997 23.799999999999997 ZT20-23 14.65 14.65 14.65