condition mean min max ZT0-3 1.05 1.05 1.05 ZT4-7 2.0 2.0 2.0 ZT8-11 8.6 8.6 8.6 ZT12-15 1.95 1.95 1.95 ZT16-19 2.1 2.1 2.1 ZT20-23 2.5 2.5 2.5