condition mean min max ZT0-3 30.9 30.9 30.9 ZT4-7 13.0 13.0 13.0 ZT8-11 12.6 12.6 12.6 ZT12-15 24.9 24.9 24.9 ZT16-19 26.3 26.3 26.3 ZT20-23 31.05 31.05 31.05