condition mean min max ZT0-3 0.75 0.75 0.75 ZT4-7 1.3 1.3 1.3 ZT8-11 2.35 2.35 2.35 ZT12-15 1.6 1.6 1.6 ZT16-19 3.15 3.15 3.15 ZT20-23 1.1 1.1 1.1