condition mean min max ZT0-3 21.85 21.85 21.85 ZT4-7 11.9 11.9 11.9 ZT8-11 23.0 23.0 23.0 ZT12-15 18.5 18.5 18.5 ZT16-19 11.3 11.3 11.3 ZT20-23 26.05 26.05 26.05