condition mean min max ZT0-3 0.95 0.95 0.95 ZT4-7 0.8 0.8 0.8 ZT8-11 1.7 1.7 1.7 ZT12-15 1.0 1.0 1.0 ZT16-19 1.2 1.2 1.2 ZT20-23 1.05 1.05 1.05