condition mean min max ZT0-3 14.1 14.1 14.1 ZT4-7 3.9 3.9 3.9 ZT8-11 9.5 9.5 9.5 ZT12-15 7.25 7.25 7.25 ZT16-19 22.6 22.6 22.6 ZT20-23 15.85 15.85 15.85