condition mean min max ZT0-3 7.4 7.4 7.4 ZT4-7 7.6 7.6 7.6 ZT8-11 7.0 7.0 7.0 ZT12-15 6.8 6.8 6.8 ZT16-19 36.25 36.25 36.25 ZT20-23 7.65 7.65 7.65