condition mean min max ZT0-3 37.9 37.9 37.9 ZT4-7 2.9 2.9 2.9 ZT8-11 25.75 25.75 25.75 ZT12-15 14.6 14.6 14.6 ZT16-19 31.049999999999997 31.049999999999997 31.049999999999997 ZT20-23 14.9 14.9 14.9