condition mean min max ZT0-3 17.75 17.75 17.75 ZT4-7 20.9 20.9 20.9 ZT8-11 6.7 6.7 6.7 ZT12-15 31.049999999999997 31.049999999999997 31.049999999999997 ZT16-19 27.25 27.25 27.25 ZT20-23 27.35 27.35 27.35