condition mean min max ZT0-3 18.6 18.6 18.6 ZT4-7 4.5 4.5 4.5 ZT8-11 5.85 5.85 5.85 ZT12-15 15.2 15.2 15.2 ZT16-19 26.0 26.0 26.0 ZT20-23 15.1 15.1 15.1