condition mean min max ZT0-3 5.9 5.9 5.9 ZT4-7 24.7 24.7 24.7 ZT8-11 50.2 50.2 50.2 ZT12-15 46.5 46.5 46.5 ZT16-19 3.7 3.7 3.7 ZT20-23 18.0 18.0 18.0