condition mean min max ZT0-3 9.0 9.0 9.0 ZT4-7 21.8 21.8 21.8 ZT8-11 3.05 3.05 3.05 ZT12-15 2.75 2.75 2.75 ZT16-19 5.0 5.0 5.0 ZT20-23 29.65 29.65 29.65