condition mean min max ZT0-3 55.5 55.5 55.5 ZT4-7 36.6 36.6 36.6 ZT8-11 28.1 28.1 28.1 ZT12-15 21.55 21.55 21.55 ZT16-19 66.9 66.9 66.9 ZT20-23 80.9 80.9 80.9