condition mean min max ZT0-3 3.8 3.8 3.8 ZT4-7 0.2 0.2 0.2 ZT8-11 12.5 12.5 12.5 ZT12-15 0.8 0.8 0.8 ZT16-19 0.5 0.5 0.5 ZT20-23 6.85 6.85 6.85