condition mean min max ZT0-3 3.5 3.5 3.5 ZT4-7 2.4 2.4 2.4 ZT8-11 6.4 6.4 6.4 ZT12-15 3.7 3.7 3.7 ZT16-19 10.9 10.9 10.9 ZT20-23 4.85 4.85 4.85