condition mean min max ZT0-3 15.5 15.5 15.5 ZT4-7 15.0 15.0 15.0 ZT8-11 8.85 8.85 8.85 ZT12-15 1.8 1.8 1.8 ZT16-19 22.75 22.75 22.75 ZT20-23 4.85 4.85 4.85