condition mean min max ZT0-3 14.75 14.75 14.75 ZT4-7 6.5 6.5 6.5 ZT8-11 16.5 16.5 16.5 ZT12-15 43.75 43.75 43.75 ZT16-19 35.4 35.4 35.4 ZT20-23 26.85 26.85 26.85