condition mean min max ZT0-3 15.8 15.8 15.8 ZT4-7 3.2 3.2 3.2 ZT8-11 7.15 7.15 7.15 ZT12-15 19.35 19.35 19.35 ZT16-19 22.85 22.85 22.85 ZT20-23 8.85 8.85 8.85