condition mean min max ZT0-3 5.4 5.4 5.4 ZT4-7 8.0 8.0 8.0 ZT8-11 5.8 5.8 5.8 ZT12-15 24.049999999999997 24.049999999999997 24.049999999999997 ZT16-19 3.5 3.5 3.5 ZT20-23 4.15 4.15 4.15