condition mean min max ZT0-3 6.35 6.35 6.35 ZT4-7 6.9 6.9 6.9 ZT8-11 10.65 10.65 10.65 ZT12-15 7.85 7.85 7.85 ZT16-19 10.85 10.85 10.85 ZT20-23 10.5 10.5 10.5