condition mean min max ZT0-3 12.15 12.15 12.15 ZT4-7 22.2 22.2 22.2 ZT8-11 13.4 13.4 13.4 ZT12-15 20.85 20.85 20.85 ZT16-19 14.65 14.65 14.65 ZT20-23 25.5 25.5 25.5