condition mean min max ZT0-3 1.85 1.85 1.85 ZT4-7 1.8 1.8 1.8 ZT8-11 9.5 9.5 9.5 ZT12-15 7.35 7.35 7.35 ZT16-19 7.5 7.5 7.5 ZT20-23 2.5 2.5 2.5