condition mean min max ZT0-3 2.4 2.4 2.4 ZT4-7 17.7 17.7 17.7 ZT8-11 3.5 3.5 3.5 ZT12-15 0.85 0.85 0.85 ZT16-19 5.65 5.65 5.65 ZT20-23 12.65 12.65 12.65