condition mean min max ZT0-3 2.85 2.85 2.85 ZT4-7 1.9 1.9 1.9 ZT8-11 6.65 6.65 6.65 ZT12-15 4.8 4.8 4.8 ZT16-19 5.6 5.6 5.6 ZT20-23 2.6 2.6 2.6