condition mean min max ZT0-3 1.25 1.25 1.25 ZT4-7 0.4 0.4 0.4 ZT8-11 1.35 1.35 1.35 ZT12-15 2.2 2.2 2.2 ZT16-19 4.4 4.4 4.4 ZT20-23 12.25 12.25 12.25