condition mean min max ZT0-3 18.45 18.45 18.45 ZT4-7 17.7 17.7 17.7 ZT8-11 12.4 12.4 12.4 ZT12-15 22.9 22.9 22.9 ZT16-19 21.65 21.65 21.65 ZT20-23 29.1 29.1 29.1