condition mean min max ZT0-3 6.65 6.65 6.65 ZT4-7 10.2 10.2 10.2 ZT8-11 47.8 47.8 47.8 ZT12-15 22.9 22.9 22.9 ZT16-19 9.5 9.5 9.5 ZT20-23 9.05 9.05 9.05