condition mean min max ZT0-3 8.0 8.0 8.0 ZT4-7 62.8 62.8 62.8 ZT8-11 3.6 3.6 3.6 ZT12-15 25.05 25.05 25.05 ZT16-19 15.5 15.5 15.5 ZT20-23 9.25 9.25 9.25