condition mean min max ZT0-3 18.5 18.5 18.5 ZT4-7 4.0 4.0 4.0 ZT8-11 19.3 19.3 19.3 ZT12-15 19.85 19.85 19.85 ZT16-19 6.7 6.7 6.7 ZT20-23 36.35 36.35 36.35