condition mean min max ZT0-3 18.0 18.0 18.0 ZT4-7 15.1 15.1 15.1 ZT8-11 21.7 21.7 21.7 ZT12-15 24.0 24.0 24.0 ZT16-19 12.6 12.6 12.6 ZT20-23 29.85 29.85 29.85