condition mean min max ZT0-3 6.25 6.25 6.25 ZT4-7 3.7 3.7 3.7 ZT8-11 4.65 4.65 4.65 ZT12-15 4.0 4.0 4.0 ZT16-19 16.35 16.35 16.35 ZT20-23 3.0 3.0 3.0