condition mean min max ZT0-3 3.8 3.8 3.8 ZT4-7 6.5 6.5 6.5 ZT8-11 2.25 2.25 2.25 ZT12-15 3.05 3.05 3.05 ZT16-19 24.3 24.3 24.3 ZT20-23 5.0 5.0 5.0