condition mean min max ZT0-3 2.05 2.05 2.05 ZT4-7 3.0 3.0 3.0 ZT8-11 4.3 4.3 4.3 ZT12-15 4.85 4.85 4.85 ZT16-19 5.75 5.75 5.75 ZT20-23 2.85 2.85 2.85