condition mean min max ZT0-3 6.3 6.3 6.3 ZT4-7 1.5 1.5 1.5 ZT8-11 17.3 17.3 17.3 ZT12-15 16.35 16.35 16.35 ZT16-19 15.6 15.6 15.6 ZT20-23 0.85 0.85 0.85